Softening (and protecting) old rubber


Paul Davock
I was just removing my rear window, as per Peter's (rizthewiz) instructions:

After lubing it with soap and water there is no way that 32 year old rubber was flexible enough to work the back flap over the lip on the parcel shelf. So I sprayed it with 303 aerospace protectant. In one hour it was supple enough to remove it.

I have found it to give excellent protection to plastic and vinyl, without the drying out or initial gloss of products like Armour All. Supposedly gives UV protection.

Paul Davock


True Classic
For years I've heard great things about 303, but Ive never tried it. Not just as a protectant but also to help old dry rubber as you say. Even suggestions of putting the part in a sealed bag with 303 then heating it in a microwave. Science tells me you cannot replace the plasticizers/elastomers in old materials, but there must be some benefit to it. Too many positive reports not to be. Thanks for reporting on it, I should get some to play with.


Darin Nelson


True Classic
303 makes a lot of similar products with different formulas for different applications. The original post by Paul was about their product # 130313, the one posted by Mike is #30350, and the one posted by Darin is #30306. I believe these are all different, but maybe the part numbers have more to do with packaging or quantity or markets (US vs Canada)? I don't know. Will all of them work the same for our intended use? I don't know. How different are they? I don't know. But I thought I'd point out that there is more than one 303 protectant # before anyone goes to buy any. If someone has more info about the various formulas please post.
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Paul Davock
OK I got curious about the numbers went to their web site:

Automotive Protectant
30381 sheets
307701 296 ml spray
307702 473 ml

Marine Protectant

30305m 296 ml
30340m 473 ml
30306m 946 ml

Outdoor Protectant

30308 473ml
30313 946ml
30320 3.78 L

Of course, the question now what is the effect of the different formulas are different?



True Classic
Today was the first day of this year's SEMA Show. After nearly 30 years of attending I've got it down to a routine; what areas to cover on which days, what to focus on and what I can skip, how to get the most out of the limited time available over its four day schedule. So today I was primarily in the 'performance' area (central hall). But on my way out I crossed through some of the restoration product companies and happened to see the "303" booth. So I stopped and talked to some of the product development guys.

First, regarding the various versions of the "303 Protectant". As I speculated they are all IDENTICAL, just relabeled for different marketing targets. It's all 100% the same inside the bottle so just look for the best price per quantity.

Second, regarding the product formula. It is a water based mixture which is why it seems to 'soak into' the material it's being applied to. Being thinner than silicone based products it is better able to be trapped in the surface pores of the underlying material. That gives it the better looking finish. The tradeoff is it evaporates more quickly than silicone products and therefore must be reapplied much more frequently to maintain the same appearance.

Third, regarding its ability to 'restore' rubber. It cannot replenish any lost chemicals into any materials. Therefore it cannot restore anything. It will help to prolong the remaining life by reducing the UV exposure, but it cannot make anything 'better' than it was (as science cannot put chemicals/elements back into something by applying a surface treatment). So sticking a rubber part in a sealed bag with some 303 and placing it in the microwave will not help anything. As for the rubber feeling softer after applying 303, that is just the coating (303) you are feeling - not the underlying material being any different. Unfortunately no miracles are happening.

They told me a interesting little story about the name. The originator was trying to create something to protect the leading edge of aircraft wings (or something like that), and kept failing. His three-hundred and third attempt at formulating something yielded this stuff...hence the name 303. It actually wasn't successful for the intended application but it was found to make the surface look great. However the 'aerospace' part of the name stuck. Well at least initially, until they decided to market it for other uses - which explains all of the various product names it now goes under.

This is all straight from the 303 product guys themselves. I admire their honesty and straightforward information about what their product is and isn't. It seems most companies will say anything to try and make more money, but they did not.

Honestly this is why I keep going to SEMA. Frankly the show cars do not attract me (with a very few exceptions now and then); for one thing you really cannot see them very well - it's simply too crowded (space and people), and for another most of them are American muscle car/hot rods (which I have no interest in). All of the products can be viewed on the internet, so not much advantage in seeing them in person unless you really must touch it to understand it. And there isn't enough time to cover the roughly 2.5 million square feet of the show in four days. But the ability to communicate face to face with the engineers, developers, testers, owners, technical types, etc, and get first hand information is invaluable to me. This is where I get most of my new product ideas to develop. And where I gauge the interest in those ideas. Plus hearing the backgrounds and back stories behind the companies, people and products fascinates me. It has become something of a annual reunion for countless great friends that I've developed over the years.


True Classic
Been using 303 on our RV for years. It's very popular in the RV-ing world. Sure works well. I Put it on at the start of the season after I take the cover off and part way throught the season as well. It brings back the shine and finish on the exterior vinyl trim pieces and painted/anodized metal. Protects vinyl graphics from shrinking from constant UV exposure. Some plastic needs repeated applications a season for it to look good. It's a UV protectant but don't think it's a restorer/conditioner type product, but could be wrong. 303 Aerospace protectant is available at most RV parts & accessories places, online or in bricks & mortar stores.

I've recently been using Meguiars vinyl & rubber cleaner and conditioner on my 600 Abarth project. I'm actually re-using the 60 year old rear 1/4 window gaskets after using it and they look and feel like new. I'm also using it on the original floor mats and wow, they look terrific. Bought a gallon of it years ago at a booth at the Monterey Historics and haven't used much of it until recently. Recommended!