Dr.Jeff
True Classic
I haven't been able to try the phosphoric or oxalic acids on the head yet. Several other things have required my immediate attention lately. Hope to be able to report more toward the end of the week.
Cleaning out coolant passages in heads?
- Thread starter Dr.Jeff
- Start date
Dr.Jeff
True Classic
I see it has been almost a year since I did anything with this topic. Frankly I've been working on other things and just left the disassembled engines sitting. In the meantime I keep reading more info and looking for better ideas.
Today I played around some more with it. I used the same roasting pan/cooker (noted in a earlier post) to heat some "Purple Power" degreaser to 200*F and let several parts soak for 10 hours. It was a combination of aluminum and iron parts; some greasy, some rusty/scaley, some with carbon deposits, some stained brown with old oil. As expected the aluminum parts took on a dark grey color, but it can be removed fairly easily if desired. I will be prepping and painting all of them so I'm not worried about the appearance. But if you want a nice shiny aluminum look then this probably isn't for you. Overall it seemed to do about the same on all of the parts - aluminum or iron. The Purple Power idea keeps coming up in my online searching. And it has worked well in my ultrasound cleaner for various things, so I was very interested to see the results. It did ok but no miracle. Lighter greasy stuff came off just by soaking, the heavier grease softened to make it easy to remove quickly with more traditional methods. It removed some light rust which really surprised me. The lighter scale was softened so it could be scrubbed off fairly easily with a stiff brush, assuming you have direct access to it - that wouldn't be possible on interior coolant passages. Carbon was about the same, softened for easier removal with a little scrubbing. The internal surfaces of a FI intake plenum cleaned up pretty well with just rinsing afterwords. But that would have been a fairly soft deposit in the first place (although it did not come off when I washed it with solvent previously). All in all the hot Purple Power soak made the actual cleaning process much easier, but the soaking time is long. At least it isn't a acid or other obnoxious agent. The cost is reasonable (about $25 for a 5 gal container), but 40-50 gallons in a large hot tank would get quite expensive.
I picked up some of the cleaning products I discussed earlier and will do some testing with them soon. But for now I am focusing on hot soak type solutions. I have the materials to make a large hot tank but need to find out if it is worth building. So first I'm testing some cleaning solutions to see how beneficial a hot tank would be. The problem is I don't want to use caustic agents because I don't plan to replace things like auxiliary shaft bearings in the block, and I also want to use it on aluminum parts. And while adding heat to any cleaning process is beneficial, the question is if it is good enough overall.
At the recent SEMA Show I discussed this topic with several people. I think the most honest answer is there really isn't a good solution, especially for difficult things like scale in cooling passages, carbon in manifolds, soft substrates, etc. Even the makers of the current commercial cleaning machines used by shops admit they don't work that well. They blame the inability to use caustic agents, but that still wouldn't answer the aluminum issue. The maker of one of the popular rust soaks (Evapo-Rust) told me if I soaked a block or head long enough it would remove the scale. When I dug deeper he said the theory was the scale is laying on top of rust and the rust remover will remove the rust - therefore taking the scale with it. Honestly I'm not buying that theory. But I may try it on a smaller part if nothing better comes up.
Something else I'm considering is going a different route. Rather than soaking in a hot tank, I'm considering using a true steam cleaner - it's like a pressure washer but kicks out a stream of steam rather than cold water. They work pretty well and with the lackluster results of everything else it may be the best alternative. I spoke with one maker of such machines and a descent small one would run several hundred dollars. That's more than I want to invest for this application so I'll do some more shopping.
Today I played around some more with it. I used the same roasting pan/cooker (noted in a earlier post) to heat some "Purple Power" degreaser to 200*F and let several parts soak for 10 hours. It was a combination of aluminum and iron parts; some greasy, some rusty/scaley, some with carbon deposits, some stained brown with old oil. As expected the aluminum parts took on a dark grey color, but it can be removed fairly easily if desired. I will be prepping and painting all of them so I'm not worried about the appearance. But if you want a nice shiny aluminum look then this probably isn't for you. Overall it seemed to do about the same on all of the parts - aluminum or iron. The Purple Power idea keeps coming up in my online searching. And it has worked well in my ultrasound cleaner for various things, so I was very interested to see the results. It did ok but no miracle. Lighter greasy stuff came off just by soaking, the heavier grease softened to make it easy to remove quickly with more traditional methods. It removed some light rust which really surprised me. The lighter scale was softened so it could be scrubbed off fairly easily with a stiff brush, assuming you have direct access to it - that wouldn't be possible on interior coolant passages. Carbon was about the same, softened for easier removal with a little scrubbing. The internal surfaces of a FI intake plenum cleaned up pretty well with just rinsing afterwords. But that would have been a fairly soft deposit in the first place (although it did not come off when I washed it with solvent previously). All in all the hot Purple Power soak made the actual cleaning process much easier, but the soaking time is long. At least it isn't a acid or other obnoxious agent. The cost is reasonable (about $25 for a 5 gal container), but 40-50 gallons in a large hot tank would get quite expensive.
I picked up some of the cleaning products I discussed earlier and will do some testing with them soon. But for now I am focusing on hot soak type solutions. I have the materials to make a large hot tank but need to find out if it is worth building. So first I'm testing some cleaning solutions to see how beneficial a hot tank would be. The problem is I don't want to use caustic agents because I don't plan to replace things like auxiliary shaft bearings in the block, and I also want to use it on aluminum parts. And while adding heat to any cleaning process is beneficial, the question is if it is good enough overall.
At the recent SEMA Show I discussed this topic with several people. I think the most honest answer is there really isn't a good solution, especially for difficult things like scale in cooling passages, carbon in manifolds, soft substrates, etc. Even the makers of the current commercial cleaning machines used by shops admit they don't work that well. They blame the inability to use caustic agents, but that still wouldn't answer the aluminum issue. The maker of one of the popular rust soaks (Evapo-Rust) told me if I soaked a block or head long enough it would remove the scale. When I dug deeper he said the theory was the scale is laying on top of rust and the rust remover will remove the rust - therefore taking the scale with it. Honestly I'm not buying that theory. But I may try it on a smaller part if nothing better comes up.
Something else I'm considering is going a different route. Rather than soaking in a hot tank, I'm considering using a true steam cleaner - it's like a pressure washer but kicks out a stream of steam rather than cold water. They work pretty well and with the lackluster results of everything else it may be the best alternative. I spoke with one maker of such machines and a descent small one would run several hundred dollars. That's more than I want to invest for this application so I'll do some more shopping.
Dr.Jeff
True Classic
I assume you mean rent a steam cleaning machine. And yes you can, which is what I will likely do. The ones under $1000 aren't really what I'd want and to get a great one is over $2000, so not cost effective for a few uses. On the other hand, renting a piece of equipment for a day is a pain in ass; I live over an hour from anywhere that rents equipment, the rental equipment is typically in such poor shape it makes the work twice as difficult, the wait to pick it up and again to drop it off is much longer than the time I'd use it, and I seldom plan ahead for such things. But it may very well be the best option.
Dr.Jeff
True Classic
Although the main topic of my discussion for this thread has been removing the scale in coolant passages, I will make a note about parts cleaning in general.
Old cars always have a lot of very greasy, dirty parts to contend with when you begin to work on them. These cars in particular seem prone to more fluid leaks than most of the ones I work on, so the old baked-on heavy build up of crud is particularly bad. Amazing where it collects and how bad it gets, often making it very difficult to remove, and I'm one of those OCD types that must get everything very clean. Using a hot solution of solvent (as opposed to any of the water based degreasers, as I described in my earlier post) has always worked best for me when soaking parts prior to scrubbing. That's one of the motivations for building a hot tank, so I can soak larger items like a block or transmission case. But another thought is to install the heating element (intended for the hot tank) into my regular parts washer instead. Then the solvent flowing through the cleaning brush might be more effective than the current cold bath, eliminating the need to presoak parts. I'm not sure just much difference the heat will make when performing a regular brush cleaning vs a soak. And while putting larger items in my parts washer is possible, it's a bit awkward. But having a large hot tank also has its drawbacks, so I'm debating on which way to go.
The parts washer I'm referring to is something like this, with one of these flow-through brushes (love that brush):
It has a circulation pump that flows plenty of volume (adjustable) through a replaceable filter before going to the brush. Another question I'm wondering is if heating the solvent will affect the life of the pump?
Hot tank vs steam washer vs heated parts washer...there's pros and cons for each. None will do everything but I'd prefer not to have much more equipment to contend with than I already have. So which will do the best for all of my needs? Who's tried any of these methods?
Old cars always have a lot of very greasy, dirty parts to contend with when you begin to work on them. These cars in particular seem prone to more fluid leaks than most of the ones I work on, so the old baked-on heavy build up of crud is particularly bad. Amazing where it collects and how bad it gets, often making it very difficult to remove, and I'm one of those OCD types that must get everything very clean. Using a hot solution of solvent (as opposed to any of the water based degreasers, as I described in my earlier post) has always worked best for me when soaking parts prior to scrubbing. That's one of the motivations for building a hot tank, so I can soak larger items like a block or transmission case. But another thought is to install the heating element (intended for the hot tank) into my regular parts washer instead. Then the solvent flowing through the cleaning brush might be more effective than the current cold bath, eliminating the need to presoak parts. I'm not sure just much difference the heat will make when performing a regular brush cleaning vs a soak. And while putting larger items in my parts washer is possible, it's a bit awkward. But having a large hot tank also has its drawbacks, so I'm debating on which way to go.
The parts washer I'm referring to is something like this, with one of these flow-through brushes (love that brush):
It has a circulation pump that flows plenty of volume (adjustable) through a replaceable filter before going to the brush. Another question I'm wondering is if heating the solvent will affect the life of the pump?
Hot tank vs steam washer vs heated parts washer...there's pros and cons for each. None will do everything but I'd prefer not to have much more equipment to contend with than I already have. So which will do the best for all of my needs? Who's tried any of these methods?
Dan Sarandrea (Phila)
Waitin' On Parts...
An old dishwasher scrounged from Craigs or perhaps a local remodeling contractor might be a good basis for a home-made parts washer/hot tank.
Dr.Jeff
True Classic
Perhaps if you could find one that is all stainless, inside and out including all the internal mechanisms. That way you could run serious solvents in it. However there may be another shortcoming to using a dishwasher. It really does not get the solution hot enough and the pressure of the spray nozzles is not high enough. Reports of trying a dishwasher have been mixed. I think it comes down to parts that would be easy to clean work well, while difficult parts (read X1/9) do not. But certainly something to consider is taking a standard S/S dishwasher and making it a super powered dishwasher.
On a similar note, I thought about using a small tankless water heater inline before my pressure washer. It would have the needed pressure but not sure if the heat level would be high enough.
Dr.Jeff
True Classic
I played around with this a little more. Remember the goal was to clean out the scale and other buildup in the coolant passages, and the cooked-on carbon deposits in the exhaust ports, on aluminum heads.
I wanted to see how much effect a "hot tank" with aluminum safe cleaners would do. I have some components that could be assembled to make a hot tank big enough to soak an entire engine in. But before building the full size version I wanted to test a few solutions with heat to see how effective they would be. So using what I believe is called a "turkey roaster" (referenced in one of my earlier posts) I submerged a trashed head in a few options. The roaster is a watertight electric cooker that can get the liquid contents up to 450 degrees F. That is well beyond the flash point of some cleaning solutions, so I could also play with various temps to see what happens.
First was a water based degreaser called "Purple Power". I've used it in my ultrasonic cleaner with decent results so I wondered how it would do just soaking in a hot solution of it. One thing I realized is you cannot keep the solution as hot as I'd like due to it evaporating too much. When it nears the boiling point steam dissipates and you lose a lot of solution, even with a lid on the cooker (you cannot fully seal the lid or it will become a pressure cooker/bomb). Keeping the temp as close to that point as possible, I let it soak for a day and a half. Unfortunately the results were not stellar; some of the surface contaminants softened quite a lot, but it still required scrubbing to remove them. And other contaminants (particularly the scale in the cooling passages and the hard carbon in the exhaust passages) weren't affected enough to really notice.
Next up was a petroleum based solvent. Some issue with the heat, if you keep it too hot it evaporates quickly. A large part of this might be due to the climate here - it is excessively dry (like close to 0 humidity), so everything evaporates regardless. But after soaking for 24 hours the results were about the same as with Purple Power.
The last solution I tried was a weak oxalic acid mix. I deliberately made it very weak because it can eat aluminum if too strong. I must have been too conservative because it really did not work well either.
Basically nothing so far has given results close to what I would like. While adding heat definitely helps, it isn't worth it because of the evaporation issue and the fact you still need to scrub the part. So the time spent soaking just does not pay off.
At some point I may fool around with a stronger solution. I'm sure soaking in a hot caustic solution will work for the cast iron block, provided you remove the aux shaft bearings (and any other non ferrous items) and fully machine every dimension/contact surface of the block afterwards. However my aux bearings (and blocks) are still within spec and I do not want to have to size new ones. So for now I won't pursue the hot tank idea any further. I guess the engines I am currently building will get cleaned as much as possible with some old fashion solvent and scrubbing. And whatever is left will continue to live in those hidden passages that are not easily reached.
I wanted to see how much effect a "hot tank" with aluminum safe cleaners would do. I have some components that could be assembled to make a hot tank big enough to soak an entire engine in. But before building the full size version I wanted to test a few solutions with heat to see how effective they would be. So using what I believe is called a "turkey roaster" (referenced in one of my earlier posts) I submerged a trashed head in a few options. The roaster is a watertight electric cooker that can get the liquid contents up to 450 degrees F. That is well beyond the flash point of some cleaning solutions, so I could also play with various temps to see what happens.
First was a water based degreaser called "Purple Power". I've used it in my ultrasonic cleaner with decent results so I wondered how it would do just soaking in a hot solution of it. One thing I realized is you cannot keep the solution as hot as I'd like due to it evaporating too much. When it nears the boiling point steam dissipates and you lose a lot of solution, even with a lid on the cooker (you cannot fully seal the lid or it will become a pressure cooker/bomb). Keeping the temp as close to that point as possible, I let it soak for a day and a half. Unfortunately the results were not stellar; some of the surface contaminants softened quite a lot, but it still required scrubbing to remove them. And other contaminants (particularly the scale in the cooling passages and the hard carbon in the exhaust passages) weren't affected enough to really notice.
Next up was a petroleum based solvent. Some issue with the heat, if you keep it too hot it evaporates quickly. A large part of this might be due to the climate here - it is excessively dry (like close to 0 humidity), so everything evaporates regardless. But after soaking for 24 hours the results were about the same as with Purple Power.
The last solution I tried was a weak oxalic acid mix. I deliberately made it very weak because it can eat aluminum if too strong. I must have been too conservative because it really did not work well either.
Basically nothing so far has given results close to what I would like. While adding heat definitely helps, it isn't worth it because of the evaporation issue and the fact you still need to scrub the part. So the time spent soaking just does not pay off.
At some point I may fool around with a stronger solution. I'm sure soaking in a hot caustic solution will work for the cast iron block, provided you remove the aux shaft bearings (and any other non ferrous items) and fully machine every dimension/contact surface of the block afterwards. However my aux bearings (and blocks) are still within spec and I do not want to have to size new ones. So for now I won't pursue the hot tank idea any further. I guess the engines I am currently building will get cleaned as much as possible with some old fashion solvent and scrubbing. And whatever is left will continue to live in those hidden passages that are not easily reached.
Dr.Jeff
True Classic
I considered that, but decided if that was the way to go then I'd just wait until the engine is finished and do it while it's running. A completed engine assembly avoids having to make block-offs. I have a old radiator that is fairly clean and could use it to let the water pump circulate the cleaning solution, eliminating the need to make a circulation system while avoiding any damage to my "good" radiator. I could also use a decent used water pump for this, then swap the new one in for the same reason. This way the solution will be heated by the engine and the head and block get cleaned at the same time. I'm not certain if there are any real advantages or disadvantages of doing it either way?
Dr.Jeff
True Classic
Thanks Glen, I have not heard of this product before. I'll try and find out more about it.
I did read an interesting article about cooling system cleaners/flushes. It gave a little chart of the various types of contamination that typically occur. I did not realize some of them even existed. For example the Dexcool issue you referenced. Since I'm not into American vehicles and have never used Dexcool, so I wasn't aware of the "black death" it can cause. The article was saying the particular choice of cleaner used should match the type of contamination, some working better for certain issues than others, etc. However the article was written by a company that makes a flush product so naturally the recommended choices were their own. But the explanation for the causes of contamination was informative. I'll see if I can find it again and add it to this discussion just for general interest.
Dr.Jeff
True Classic
The literature for "Irontite Thoro-Flush" says it will unplug cooling systems that are completely blocked. It also says it can be used to clean blocked oil coolers on diesel applications (off the vehicle), and other similar uses. And the instructions say it does not take long. Usually that means it is a caustic agent, so I looked further.
According to the SDS, "Irontite Thoro-Flush" is basically TSP (trisodium phosphate). And the bottle says it comes as a powder, which is how TSP is usually sold. TSP was a common household cleaning product for decades and it was very inexpensive; used to clean walls before painting, decks, equipment, floors, etc. It is strong but I don't think it is really caustic (need to research it more). I read once where it was a decent degreaser for engines, etc, but I never tried it; I wanted to several years ago but TSP was no longer available on the shelf in Calif (typical CA regulations). A "substitute" product was labeled as TSP but wasn't the same and I doubt it would work (the "safe" versions of anything usually don't). However it might still be available in other states, or perhaps it has since been deregulated in CA, or maybe it can be ordered online regardless where you live (I've never quite understood that one). Might be worth getting some and experimenting with it for multiple uses, including cleaning the cooling system.
https://en.wikipedia.org/wiki/Trisodium_phosphate
According to the SDS, "Irontite Thoro-Flush" is basically TSP (trisodium phosphate). And the bottle says it comes as a powder, which is how TSP is usually sold. TSP was a common household cleaning product for decades and it was very inexpensive; used to clean walls before painting, decks, equipment, floors, etc. It is strong but I don't think it is really caustic (need to research it more). I read once where it was a decent degreaser for engines, etc, but I never tried it; I wanted to several years ago but TSP was no longer available on the shelf in Calif (typical CA regulations). A "substitute" product was labeled as TSP but wasn't the same and I doubt it would work (the "safe" versions of anything usually don't). However it might still be available in other states, or perhaps it has since been deregulated in CA, or maybe it can be ordered online regardless where you live (I've never quite understood that one). Might be worth getting some and experimenting with it for multiple uses, including cleaning the cooling system.
https://en.wikipedia.org/wiki/Trisodium_phosphate
dllubin
Don
I used TSP for painting quite a bit. In addition to cleaning, I think it would slightly etch the old paint for better adhesion. I've got an old box somewhere. Sounds like I better hang on to it as safe stuff often does not work as well as the unsafe stuff.
Dr.Jeff
True Classic
I looked for info on TSP's effect on aluminum, brass, bronze, etc.
TSP is alkaline (a base), but for the most part not a really aggressive one. The actual pH will depend on the dilution ratio, so it can be a weak or strong base. Strong bases act similar to strong acids, therefore a really strong solution of TSP could slowly etch away at soft metals (but it does not affect brass and bronze as much as it does aluminum). However a weaker solution of TSP actually prevents erosion of aluminum...really interesting and frankly I'm not sure why, but that's what the literature said. In fact it is used as a scale prevention additive in boilers with all types of metal components. So perhaps there is something to using this for a cooling system cleaner.
The SDS for Thoro-Flush says it also has salt in it. According to what I read that does not change the pH, but does act as a mild buffer to further prevent damage to aluminum. Therefore the product as marketed should be safe to use in whatever dilution they recommend. Unfortunately they do not disclose the percentages of TSP and salt, nor the concentration/pH when mixed as directed. So using regular TSP instead will require a bit of trial testing to determine the best ratio with water (i.e. solution concentration and pH level). But to put it into perspective TSP is used in some food products and certain athletes consume it to enhance performance...so it must not be that dangerous on your engine parts.
I also saw mention of using a heated TSP solution for cleaning parts. Gets back to my earlier posts about adding heat to speed up a process. Maybe I'll give the hot soak one more trial; turns out it is easy to buy TSP online pretty cheap.
TSP is alkaline (a base), but for the most part not a really aggressive one. The actual pH will depend on the dilution ratio, so it can be a weak or strong base. Strong bases act similar to strong acids, therefore a really strong solution of TSP could slowly etch away at soft metals (but it does not affect brass and bronze as much as it does aluminum). However a weaker solution of TSP actually prevents erosion of aluminum...really interesting and frankly I'm not sure why, but that's what the literature said. In fact it is used as a scale prevention additive in boilers with all types of metal components. So perhaps there is something to using this for a cooling system cleaner.
The SDS for Thoro-Flush says it also has salt in it. According to what I read that does not change the pH, but does act as a mild buffer to further prevent damage to aluminum. Therefore the product as marketed should be safe to use in whatever dilution they recommend. Unfortunately they do not disclose the percentages of TSP and salt, nor the concentration/pH when mixed as directed. So using regular TSP instead will require a bit of trial testing to determine the best ratio with water (i.e. solution concentration and pH level). But to put it into perspective TSP is used in some food products and certain athletes consume it to enhance performance...so it must not be that dangerous on your engine parts.
I also saw mention of using a heated TSP solution for cleaning parts. Gets back to my earlier posts about adding heat to speed up a process. Maybe I'll give the hot soak one more trial; turns out it is easy to buy TSP online pretty cheap.
Dr.Jeff
True Classic
This discussion about TSP reminded me. A few years ago when my dad passed I was left with the task of cleaning up his property, including a very heavily packed garage. One item I remember seeing was a box of TSP. Today I looked back through a couple boxes of left over stuff and found it. It is a 1 lb unopened box that has probably been sitting on his shelf for close to 30 years. Old enough to be the "real stuff". I don't know if there is a "shelf life" for TSP, but in this arid climate there isn't any chance of moisture contamination. So figured I'd give it a try.
TSP is described as a white crystalline granular power. Inside the box was a mix of white and yellow crystalline powders. They were very distinct from one another. Looking on the label I see that commercial TSP isn't straight TSP, but a mix of TSP and sodium carbonate (yielding 6% of elemental phosphates). Apparently one of those two compounds had turned yellow with age. The 1 lb box was enough to make 3 gallons at the concentration recommended by the instructions, which is enough to completely submerge a head in my small hot tank (turkey broiler). Now that head is soaking at 200 degrees F overnight. We'll see what happens tomorrow.
EDIT: By the way, the "sodium carbonate" listed on the package of TSP is a form of sodium salt - the other ingredient listed on the SDS for Irontite's Thoro-Flush cooling system cleaner. I'm now guessing that product is just repackaged TSP.
While I was looking for the TSP I also found a couple cans of oven cleaner. That's an item internet lore swears is a fantastic engine cleaner. Since I don't plan on cleaning the oven anytime soon, I decided to give it a try as well. So there is another head covered with oven cleaner also sitting overnight. Normally I would completely dismiss the internet claims about it, but interestingly within seconds of the oven cleaner hitting the dirty areas it turned dark brown (the color of the heavy oil/grease build up on the head). Maybe there is something to this after all? We'll see.
TSP is described as a white crystalline granular power. Inside the box was a mix of white and yellow crystalline powders. They were very distinct from one another. Looking on the label I see that commercial TSP isn't straight TSP, but a mix of TSP and sodium carbonate (yielding 6% of elemental phosphates). Apparently one of those two compounds had turned yellow with age. The 1 lb box was enough to make 3 gallons at the concentration recommended by the instructions, which is enough to completely submerge a head in my small hot tank (turkey broiler). Now that head is soaking at 200 degrees F overnight. We'll see what happens tomorrow.
EDIT: By the way, the "sodium carbonate" listed on the package of TSP is a form of sodium salt - the other ingredient listed on the SDS for Irontite's Thoro-Flush cooling system cleaner. I'm now guessing that product is just repackaged TSP.
While I was looking for the TSP I also found a couple cans of oven cleaner. That's an item internet lore swears is a fantastic engine cleaner. Since I don't plan on cleaning the oven anytime soon, I decided to give it a try as well. So there is another head covered with oven cleaner also sitting overnight. Normally I would completely dismiss the internet claims about it, but interestingly within seconds of the oven cleaner hitting the dirty areas it turned dark brown (the color of the heavy oil/grease build up on the head). Maybe there is something to this after all? We'll see.
Last edited:
Hybridfiat
Power costs money, more power cost more money
There is a product for cleaning aircon condensers and intercoolers called Condenser cleaner. It is made up of two strong bases, sodium hydroxide and potassium hydroxide. It cleans aluminium like nothing you have ever seen before. BUT, it will take your skin off faster than a sharp knife!
Follow the precautions to the letter or say hello to your local burns unit.
This is meant for thin walled aluminium radiators so I guess it will be ok in an engine as long as it is flushed well afterwards.
Follow the precautions to the letter or say hello to your local burns unit.
This is meant for thin walled aluminium radiators so I guess it will be ok in an engine as long as it is flushed well afterwards.
Dr.Jeff
True Classic
I'm familiar with that, have used it several times on both home and automotive AC systems. Never thought of trying it for this application, so might have to give it a test.
One thing that is good and bad about aerosol products like condenser cleaner or the oven cleaner I'm currently playing with is their "foaming" action. It is designed to expand and foam up in order to help get into hidden places, which is good here because you cannot reach most of the coolant passages. But it also makes it difficult to control (seems to get everywhere) and it evaporates very quickly (especially in this arid climate). So multiple applications are necessary in order to keep the surfaces covered while it works. But any remaining foam from the prior application prevents more material getting through - just starts backing up and foaming too quickly. Messy to deal with, but I'll see how well things go later today.
Dr.Jeff
True Classic
Today I rinsed and inspected the two heads; one was in a 200 degree F heated TSP solution for 24 hours, and the other I tried a few doses of oven cleaner on. The outcome for both was nothing special, about the same as with the Purple Power (see my earlier posts). Both caused the aluminum to turn a fairly dark shade of grey. The oven cleaner was much like using a spray foaming engine degreaser (like "Gunk"), and actually less expensive. But the fumes make it noxious.
Really nothing I've played with has been very effective so far. Especially on the worst deposits - scale in the cooling passages and carbon in the exhaust passages. And those were the ones I'd hoped to find a solution for.
I'll have to look back and see if there were any other suggestions to try. One that I'd like to do is the pressure steam cleaner. I'll see what's available to rent. But before I do that I should get a bunch of parts ready, set up an area to do it, and make a plan so the rental is worth the effort.
Really nothing I've played with has been very effective so far. Especially on the worst deposits - scale in the cooling passages and carbon in the exhaust passages. And those were the ones I'd hoped to find a solution for.
I'll have to look back and see if there were any other suggestions to try. One that I'd like to do is the pressure steam cleaner. I'll see what's available to rent. But before I do that I should get a bunch of parts ready, set up an area to do it, and make a plan so the rental is worth the effort.