Seam Sealer

Can someone educate me on seam sealer. I've seen some guys talking about it and using it. What does it do, and where should you use it? Should you use it only on heavy duty welds, or everywhere? Thanks.

use it anywhere there is a seam that water or fumes can get to. And anytime there is a seam without but welding.

keeps the cancer outta your sheetmetal, very necessary unless you only plan on keeping your truck a few years then junking it.

I use liquid nails. I would use a caulk gun to run a bead along the new seams (floorpans, door skins, etc..) and a small paint brush dipped in thinner to smooth it over. It always turned out nice and would not shrink over time like seam sealer and crack under the paint.

seam sealer doesnt crack unless you buy cheap garbage. use the epoxy type. i use the fusor brand, 3m also makes it. ask your local paint shop. dont use the cheap crap because its cheap crap.

WOW! that is an interesting explanation!

words to live by. you can quote me if you'd like. lmao...

I don't know how much seam sealer is going for these days but liquid nails has always been cheap! Especially when you replace all the floor pans in a '49 Buick and have to seal it all up. Plus, it lasts forever, and you can paint over it.

So if I'm tubbing my bed, I should use it. After welding, should I apply it before any body filler? Also, is it sandable?

I use an SEM brand seam sealer, or the 3M type, because I can get them at the paint shop. They have tubes that are pressurized for easy application. But I just buy the slightly larger one and use a calk gun to apply it. They are the same price, so it makes sense to me to get the larger one. I use about 1-1.5 tubes to do a bodydrop on a mini truck. I lay it down on every seam, without smoothing it out. By the time I am done and ready to smooth it, it has set up a little bit and is very easy to manipulate. I just wear some nitrile gloves and run my finger across the seams and work it how I need to.