Bondo VS Seam sealer

[JCA1972]

Hi to all, I am restoring my 71 C-10 and I recently replaced the floor panels and inner rockers, I don't have a great welding machine and I could not completely seal weld the floor panels in. I have pin holes here and there. I went to the local auto paint supply and their cheapest seam sealer is around $20.00, and you need a $57.00 dollar caulking gun to apply it. I am wondering if I could just use Bondo to seal all the seams.
What do you guys think.

[rage'nrat638]

i would not..that is the flex area. and it's just going to pop out and kill your 3000.00 paint job for 70.00. that caulk gun and seam searler rocks

[Huck]

Eastwood sells brushable seam sealer for around $20. that works super. BONDO is porous which means moisture will penetrate it especially when it cracks due to stress but even without cracks, water will penetrate unless you seal it with a good epoxy primer or other water sealing paint.

[centsless]

Bondo is NOT waterproof. It will allow water in and let the rust begin.... You could use Mar-glass made by marson, it is like a fiberglass paste. We used mar glass on the inside of the cab, seam sealer on the underside, and a two part epoxy sealer in the drip rails.

[glock35ipsc]

The brush-on seam sealer from Eastwood works well, and they also have a tube of seam sealer that works in a regular old silicone/RTV type gun.

[CMars45000]

3M has a general purpose seam sealer that will work in a regular caulking gun...Don't know the number of the top of my head but it comes in a blue and white tube... and it is like $16 a tube

[49studebaker]

I bought seam sealer at Carquest that actually came in an areosol can. Don't remember what I paid for it, but you bend the nozzel/tube and the seam sealer flows out. Pretty cool, just can't remember the brand.

[mac]

I have buddy that does a lot of insurance body repair. He has begun using a type of LIQUID NAIL called "FRP" that mimics the seam sealer. It even works as a sound deadner if you put it on and let it begin to set up then use a mortar trowel with the 1/4" notches to spread it. It comes in a gallon can and is off white in color.

He has a Harley Ford F250 in his shop with the cab completely stripped out. The factory sound deadner is painted on and troweled like tile mud too. All up on the fire wall and under the seats. The Liquid Nail stays flexible and doesn't stink once its set up. May be a hillbilly fix but its cheap.

[Fastfun]

I just purchased some brushable seamsealer that is self leveling so you do not see the brush marks for $18.00 at a paint supply store and it works great.

[Trey`]

I agree go with the seam sealer and Cmars45000 is right 3m does make one. I have it in the shop and if we were'nt under a Tornado watch and it was'nt raining I would get the part # for you. We use a urethane seam sealer from IES at the body shop I work at and you do have to have a special gun for it, but not the 3M, I think it is called something like "Fast and Firm"?

[timcos]

Here's a goofy question...What is seam sealer used for (other that the obvious...to seal a seam?

Thanks,

Tim

[Aarons72s]

As for price of seam sealer that is way over priced for a tube of it. Go to an oreillys and buy it, like 9 bucks for the 3m stuff or I use transtar stuff which is cheaper. As for other uses for seam sealer I use it where bondo no good, ie drip rails, to blend rockers into the cab. Also here is a rigged use for it, did it in autobody class, used it as an adhesive to repair a 78 ford door panel. I use the seam sealer on stuff that will recive automotive paint and you will see. But when it comes to floors I use a hardware store paintable siliconized acrylic caulk. They got it any many colors, I use black alot, and it seams to bre alot easier to use than seam sealer. I have used liquid nails as a seam sealer to in the cowl area.

[JCA1972]

Thanks for your help guys, I ordered some of this stuff from Por-15, it comes in a squeeze tube.

POR PATCH™ - Black
[PPB] $17.25

[timcos]

So what is seam sealer? I know it seals a seam....but if you grind don't you have a smooth seam to paint?

Tim