What's the right tool???

[Porky]

Hi, the chassis and engine work on my adopted Mark 3 build is just about finished and over the winter I want to get started on the body. With the cold temps finally coming, I'm not going to go any filler but I want to get started knocking down the seams, fitting the doors, hood and trunk lid.

So my first question is what you folks have found to be the best tool for knocking down the seams. Should I just use the DA or would a die grinder with something like a 2 inch sanding wheel or stone make more sense? I know that I need to open up the seams but I have also read that some guys have taken it too far and I don't want to make more work for myself.

Any insight from those that have done this is much appreciated.

Thanks

Joe

[Jeff Kleiner]

DA with 40 grit to knock down the mold parting lines (they aren't seams). If it is an early Mk3 you might find a line of gelcoat down into the glass. If so that should be ground out (a round cutter on a die grinder or Dremel works well) and the valley filled with 3M HSRF.

Jeff

[Porky]

Thanks Jeff. So those are mold parting lines and not seams. I see. That sounds good from a structural standpoint.

While I have you. What tool would you recommend for trimming the excess material on the fender lips?

Thanks again.

[Jeff Kleiner]

I use a pneumatic die grinder with a thin kerf 3" cut off wheel.

Jeff

[Porky]

That was my thought also. Thanks for your help Jeff.

[Porky]

Just to follow up on this thread, I ground out the parting line on the pass side today and there soft spots and voids. There were also places where the gel coat and underlying fiberglass seemed to be pretty solid. Should I just look for the soft spots and fill only them or go down all the parting lines and remove a shallow valley and then fill in with HSRF? I would rather be safe than sorry but also wouldn't mind avoiding needless filling and sanding. Thoughts from anyone? My chassis number is 5612 if that sheds light on anything.

Thanks

[Jeff Kleiner]

...My chassis number is 5612 if that sheds light on anything.

Thanks

That vintage is likely to have gelcoat in the parting lines. Do you have dark stripes kinda' like this?

http://i269.photobucket.com/albums/jj43/jkleiner/100_0864.jpg

http://i269.photobucket.com/albums/jj43/jkleiner/100_0866.jpg

http://i269.photobucket.com/albums/jj43/jkleiner/100_0871.jpg

If so that's gelcoat. Before deep grinding try going a little farther with the DA; if you're lucky it may only be in the first layup. Speaking of "shedding the light" put a shop light under the body while you're working on eliminating the line; the translucent 'glass lets the light shine through but the gelcoat does not.

http://i269.photobucket.com/albums/jj43/jkleiner/100_0874.jpg

When the stripe disappears you're good!

Good luck,
Jeff

[Porky]

Yes Jeff, my parting lines look much like that. I have a bunch of voids and holes to which I applied an awl and found them to be fairly brittle. So what I need to do is get the gel coat out of the parting lines so that I'm down into fiberglass? I used the light and was horrified as to how thin the structure was after I had used the grinder on the pass side.