3M cavity wax in longitudinals

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John Lindstrom
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3M cavity wax in longitudinals

#1 Post by John Lindstrom »

Has anyone else used 3M cavity wax in their longitudinals?

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David Jones
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Re: 3M cavity wax in longitudinals

#2 Post by David Jones »

John,there is a product that can still be found called Waxoyl that was used in the UK many years ago where cars came with rust from the factory. It was/is still sold over here in the States I believe. Try a google search, from all a counts it did work but I know not how effective it was/is.
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Martin Benade
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Re: 3M cavity wax in longitudinals

#3 Post by Martin Benade »

I used to apply Waxoyl to new Subarus. They claimed a slight fog of it inside a door would protect the whole door. My feeling was that the only real protection came from warranty, if applied according to their directions. I do believe if you got a large quantity of it in the right places, it would be a helpful sealant/rust preventitive, like lots of other rust inhibitors on the market. 3M sells spray cans of "Inner panel rust preventitive" that I think are good, not sure if that is cavity wax. Will you be driving your 356 in Cleveland's winter snow and road salt?
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Bruce Smith
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Re: 3M cavity wax in longitudinals

#4 Post by Bruce Smith »

I used Wurth Cavity Protection Spray when I reassembled the front end on my 911T. It's like Waxoil to displace water in seams, folds, etc. Good insurance but I'll probably never know if the stuff does what it claims.
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Re: 3M cavity wax in longitudinals

#5 Post by Jay Darlington »

I've used it several times, I've been in the restoration businesses for over 40 years mostly hot rods and vintage American stuff. the 3m cavity wax kit comes with 3 wands 8, 24 and 34" seems to work well much better than having bare metal exposed to the elements. one thing to consider is not to plug and drain holes. imagine a 356 door with a nice layer of cavity wax when it left the factory.
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Re: 3M cavity wax in longitudinals

#6 Post by M Penta »

I used the fluid film spray kit in my C. First I blew out and vacuumed out the longs with a tube attachment through (2) 1 1/2" holes, then sprayed every blind cavity in the car with various wands. It took a while but was a satisfying job. There was no need to open the longs on my car when I refurbished it, so they were not freshly primed/painted inside and were dirty with light rust, so I just cleaned them out best I could and sprayed the fluid film.

Last winter i did my 2003 Jetta commuter with fluid film. I removed wheels, mudflaps, treated minor rust under mudflaps, removed all body plugs and sprayed in fluid film. Took several days to prep and apply (most sane people would not bother), but it see's alot of salt and has close to 300k and the usual rust prone area's are clean (except the hatch has spots under window).

I have also used cosmoline on some other cars that I drove daily in winter, one of which was an 82 MB wagon which saw like 10 vt winters. I removed interior panels, carpet, etc and sprayed the crap out of that thing inside every nook and cranny. I cleaned/resprayed all area's in the unibody with removable plugs a few more times over the years. It was alot of work, and again - most sane people would not bother, but it definitely was worth the effort since the car really did not rust at all during my time of ownership.

Getting kind of off topic now, but this year I am having my Wifes Jeep Wrangler done at a shop. Last Fall when we got it I had it done at a shop in town that uses lanolin (which is pretty much all fluid film is). This year we are having it done at another place that everybody swares by that uses heated oil of some sort.
I pressure wash the frame out since it is amazing how much silt builds up in there living on a dirt road. Even with the oil undercoats I will still completely clean it out and redo it ever year. Its frusterating how bad the paint is on underside, axles, etc. I may paint some of this next year.

Anyway, I would not hesitate to use the 3M product or any of the others I mentioned. I did like the cosmoline alot since it went on like penetrating oil and then firmed up into a soft wax, which sounds alot like the 3M stuff. Make sure you do any paint or undercoat work first.

Can you tell I hate rust? its tough being into cars and living in such a heavily salted area!

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