The Stovebolt Site Forums The Shop Area Paint and Body Shop To Undercoat or not

I'm to the point of painting my inner fenders, the fenders themselves are next. I had to weld up some cracks, then put rust encapsulator on the outside where there was still some light surface rust that didn't come off with the wire wheel. I have primed both sides and intend to paint with a flat black paint. Just wondering what the thoughts are on undercoating the outer side before assembly. This is my first project so thought I would ask you guys that have been there and done that. The truck will never be driven in bad weather, at least not by me and will be stored inside. Thanks

Steve

Another options is chip guard. I have it on the underside of the fenders and hood. Has been on about 15 yrs, can't see much deterioration although it's only been in the rain about 3 or 4 times.

Ok, is this Chip Guard a type of undercoat or is it more like the spray on bed liner material?

SEM products - Chip Guard

Chip Guard (acrylic coatings that match light to medium OEM textures)

Pro-Tex™ 2K Chip Guard Kit (two-component, urethane, textured coating)

Heavy Texture Chip Guard (spray can)

Truck had it on when I bought it but I used SEM for a repair on the underside of the hood. Matched perfectly.

Tim,
This site has lots of products but I don't see any way to order any. Any idea who might carry these products.
Thanks

Steve

Steve,

Search/Google/etc SEM undercoating

At least one autobody store near me sells these products. Call local autobody/autoparts stores, or, buy on-line.

I am thinking about undercoating my fenders. They are prone to getting stars in the paint from rocks kicking up. Havent decided for sure what exactly to use, so this is a helpful conversation.

I posed the question here since so many have done restorations on these old trucks, I really don't know if I should do it or not. I actually have several cans of undercoat I got at some point from Eastwoods. I am thinking it might be good to protect from gravel damage under the fenders like what you are talking about. I think these inner fenders actually had some undercoat from way back in places. I used diesel fuel to get it off, there was also a good amount of old tar too. I'm still thinking on this.

Steve

I am in total agreement. That decision is HARD seeings the hours I spend scraping, sanding, blasting old undercoating. But the way I see it, if it were a trailer queen you are going for.. something that is trailered to a show, get your trophies then take it back to its environmentally controlled shop, then no undercoating.

If you plan on driving it to car shows, my thinking is, they will doc you for stars in your paint due to rocks, etc, MORE than they would for the undercoating. But I could be wrong.

I once used an undercoating that worked very well but it got gooey if there was an oil leak. Wound up taking it all off. Replaced it with a 3M product (don't remember which one) and was very happy with it. I'm going to undercoat the fenders on my truck for sure. Primary benefit for me is rock protection. Corrosion protection will be handled by the epoxy primer.

Dennis

Unfortunately my old truck won't be a show truck in any way shape or form. I am hoping it looks good but with my amateur work I would be laughed out of a show like that. I can do the mechanical work but this is the first time I have tried body work, I've found the paint is the hardest at least for me. I will probably use it some around here, maybe a local parade. It will be stored inside and won't be in the weather. The thing is our streets are gravel so protection from rocks is probably a good idea. At any rate is will be a lot better than the beat up rusted thing I bought.

Steve

The most difficult to remove and best preserved area I ran into on my project was the roofing tar on the inside of the fenders. Even found a few pieces of gravel lodged in it but no stars in the paint. ..

I haven't gotten to the actual fenders yet, they are off the truck but appear to possibly have something underneath like what you are talking about. I need to get the inner fenders done first then will tackle those.

What about spray on bed liner. I've sprayed it and it's very easy to spray even for an amateur such as my self.

3M Body Shutz is what my PPG supplier recommended for undercoating fenders, etc. I feel its necessary to keep those rocks from causing Stars in the paint. I am told it works great right out of the aerosol can, but they do have a special application gun for it too.

The worst part of cleaning and rust repair on my fenders was the "tar" like stuff that the factory used to undercoat them. That was after 60 plus years of hanging out and, it worked. No rust under that stuff. It had fallen off in places and rust was there. The modern stuff that is from the same manufacture as the paint you use is what I would recommend. The factory had some under there so I would think a judge would have to expect it....but then maybe not. I know some ACMA judges and they are a fussy bunch.

Then you had better bring this along with you if you are
planing on being judged:
http://www.pbase.com/dennygraham/image/160531668

dg

Denny: Where do you find this stuff? Nice information. Thanks!

FAM.....by now you should have one Steve.

dg

My 52 had that tar-like stuff, but it was applied for free by the highway department. It perfectly preserved the original Forester Green paint on the underside of the front fenders (a much debated topic BTW) and on the parking brake bracket.
Carl

Here is what i'm doing for undercoat. The goal was uniform appearance and protection. I used a propane torch and putty knife to remove the old road tar down to the orig blue paint. Then 80 grit on a dual action sander. Then primer and a thin coat of 3m bodyschutz from a gun. To finish it off I rattle canned a topcoat of gloss black (if you can call the underside of a fender topcoated). The result was clean and hid all the minor hammer marks from metal work.[IMG]http://i867.photobucket.com/albums/ab231/marko27271/SAM_4798_zpseufvua5x.jpg[/IMG][IMG]http://i867.photobucket.com/albums/ab231/marko27271/SAM_4812%20-%20Copy_zpsoww0ocol.jpg[/IMG][IMG]http://i867.photobucket.com/albums/ab231/marko27271/SAM_4814_zpsxfld3tmi.jpg[/IMG]

Denny is right. I need to spend the money for the assembly manual. But there are so many places to spend both time and money. Thanks for the posts. I for one find them very helpful.

I highly recommend the FAM, as well. Not much of an expense for all the information you gain.

Two things that have made working on my truck easier & more educational: 1) The search function here on Stovebolt, and 2) Finally purchasing the Factory Assembly Manual.(Everyone should have a shop manual as well; but it is accessible online thanks to Mr. Hardy)

Brad

Did they make a FAM for the '37?

Quick search and I can't find anything before '47.

No assemble manual for '37