seam sealer questions....

[The WidowMaker]

i just put a coat of epoxy on the bottom of my 70 velle. the plan is to cut the trans and driveshaft tunnels, do a mini tub, fix a little rust that was under the rear seat??? and then rough it up and put another couple coats of epoxy on it. i then want to shoot the bottom with g2, use a little rage to smooth some stuff out, shoot my sealer and then base and clear it. i was originally going to weld EVERY seam and smooth the whole bottom, but the amount of work needed is a little too much even though it would be bitchen when done. so now im left with seam sealing the joints.

so now the questions...

im going to use a good 2 part sealer from sem, 3m etc... but whats the difference btwn the firm and soft. now i obviously know ones firm and ones soft, but what are the advantages/disadvantages/uses for the two? i would think that the firm would be better for me since the bottom is getting based and cleared and it would hopefully keep the paint from chipping. should i do my filler work and then seam sealer? would the g2 flake off of the seam sealer if i shot it after it was sealed? if i sealed every seam on the bottom of the car, would i cause any harm? i thought the only seams that didnt get sealed were the ones between the floor pans and braces, although ive seen pictures of guys doing this.

also, how many tubes to do a car. sem sells them in 7 oz tubes. i would think no more than 3 tubes would do it. am i right?

thanks, Tim

[oestek]

The 3m Heavy Bodied seam sealer (pn 051131-05887) is recommended for vertical surfaces, and the self-leveling (pn 051135-08307) is recommended for flat horizontals. The self-leveling will smooth itself out, won't shrink, and is paintable in an hour or so. The Heavy Bodied is paintable faster, but won't smooth itself out as much, so you'll need to brush or wet-glove it. We use both with the air-operated gun. Hope this helps.

[The WidowMaker]

well its on a rotisserie, so i think i could use the self leveling for everything once flipped up side down. how far would that flow on a vertical surface?

do you guys ever do filler work over the top of the seam sealer, or would you do it under?

thanks, Tim

[oestek]

The self leveling doesn't flow that much vertically.. you just have to practice with it and see how it works for you.

It depends on the seam if it's over filler. I'll say we rarely use sealer over filler... once the metalwork is done, the metal seams all get filled, and then the car goes to filler. From there, certain exterior seams may get filled, but not usually over filler.

[The WidowMaker]

thanks for the info. ive checked out your videos and the application looks pretty straight forward. i still kind of wonder about the filler issue. i plan on shooting the whole bottom with a polyester primer, so i dont know if i should do this before or after the sealer. there shouldnt be and hand applied filler (rage) on top of these seams since the major smoothing isnt any where near these spots. like i said before, the original plan was to weld the whole seam, grind, epoxy, rage, g2 and prime for that completely smooth look.

how tough are these products? do they give a lot? if they arent that flexible, i wouldnt see an issue with applying the g2 over the top of them. the seams themselves also shouldnt give much since theyre spot welded together.

btw... any videos on block sanding body lines? ive searched your site and cant find any.

thanks, Tim

[oestek]

OK, If I'm understanding you correctly, you want the seams to visually go away. I just had a conversation with our body man John who suggested that you finish the bodywork on the panels... filler, poly, primers, etc., and stay away from the seams with those products. Then, go back to the seams, tape off a decent amount on both sides of the seams. Your intent is to create a smooth path for the sealer to occupy, maybe 1/2 inch away from the seams on both sides. Then, lay in a fairly heavy line of self-leveling sealer and go over it quickly with a smooth filler spreader. Your goal is to force the sealer into the seam, and also create a smooth transition between the two panels with the sealer. Then pull the tape before it hardens. Finally, you can scuff the sealer, spray your paint sealer, base, and clear over it. The problem is that seam sealer is flexible and fillers and polys aren't, so if the seam flexes, it will pop the filler off if you mud over the sealer. Make sense?

- Kevin

[The WidowMaker]

yep thats what i was thinking. the filler would pop off the sealer beacuse it was flexible, but i wasnt sure if the sealer would have a problem sticking to the filler.

thanks, Tim