KBS Undercoating?

[Pete Lenzini]

I see some positive comments on KBS gas tank sealing products but nothing on their undercoating. The website shows a rubberized and an asphalt undercoating, both reasonably priced in aerosol or quart and gallon sizes. I want to touch up some areas where the old (asphalt or tar based?) coating has dried out and I've scraped off mainly on the front diagonals. Would you use the rubberized or the asphalt-based? I'll probably brush it on after priming the bare metal with Zero Rust, POR 15, Rustoleum, et al.

Thanks,
Pete

[Andrew Neville]

Hi Pete , I used the Bitumen based product from 3M , you'll have to purchase the spray gun to suit the can , works great and has the factory look.

[Pete Lenzini]

Thanks Andrew. I know there's a big variety of undercoatings out there and I like 3M products, but I'm particularly interested in people's experience with KBS.

Pete

[Jules Dielen]

I see some positive comments on KBS gas tank sealing products but nothing on their undercoating. The website shows a rubberized and an asphalt undercoating, both reasonably priced in aerosol or quart and gallon sizes. I want to touch up some areas where the old (asphalt or tar based?) coating has dried out and I've scraped off mainly on the front diagonals. Would you use the rubberized or the asphalt-based? I'll probably brush it on after priming the bare metal with Zero Rust, POR 15, Rustoleum, et al.

Thanks,
Pete

I personally would not brush it, as it won't look anywhere close to the rest or what it looked like originally. Spray gun is the way to go. I have not heard of KBS, i have only used würth.

[Alex Parmenter]

I use and recommend Wurth undercoating, great product!

As a side, I’m not a fan of Por15, it got a load of hype in the classic car world years back. I’ve tried it years ago and seen a few big issues with it from others if surface prep is not 100% and even then I don’t like the way it forms a ‘skin’ that water can get under. Also it’s horrible stuff to work with. I think you’re much better off with a good 2 part epoxy primer and topcoat. You can get the 2K spray in aerosol spray cans also, just be sure to use the appropriate PPE. Eastwood also sell some good 2K chassis paints

[Martin Benade]

If you are painting and preserving a rusty old floor, it’s outstanding. On new metal it’s pretty much useless.

[Vic Skirmants]

If you are painting and preserving a rusty old floor, it’s outstanding. On new metal it’s pretty much useless.

Matin; which product are you referring to as "useless".

[Martin Benade]

Sorry, I was referring to POR 15.

[Pete Lenzini]

I basically agree with Martin's comments on POR 15 except that I don't think it's useless on new metal. And Alex is correct that preparation must be 100% and a PITA to work with but worth it to me. My experience with it has been on off-road 4x4s in woods, dirt and mud, mostly frames and undersides, and the stuff is realty tough and doesn't chip or scratch. I have odds and ends of it left over from prior jobs and thought I might use it as a base for the rubberized or asphalt-based undercoat.

Biggest problem with POR 15 in my experience is the relatively small window for top or second coating it. Wait too long and the top coat won't stick and it's nearly impossible to roughen it to improve adhesion. I've overcome this by using their Tie-coat primer under the top coat.

Still haven't heard any comments on the KBS (seems to me sort of a POR 15 wannabe) undercoating. Mainly whether to use the rubberized or asphalt based. The stuff is half the price of Wurth and others.


Thanks,
pete

[Jim Wayman]

Andrew

Is the 3M product you use their #08881?

[Andrew Neville]

Hi Jim, the product I used is the #08861.

[Jim Wayman]

Thanks, Andrew