MKIII Body work

[CobraSnake7]

When I built my MKIII I was told to grind out the joint seams at the front, the fender tops, etc, and then fill them with HSRF (high strength repair filler, a 3M product), and then bondo over them to finish. My seams were horrible so I did this 10 years ago on mine. Now I am working on another MKIII that has set for about 7 years, and the seams are very, very good. My question is do I have to dig these seams out as well, or just sand them smooth, and bondo to my liking. It seems a waste to grind out these seams, as they are about perfect as is.

[skullandbones]

Mine was more on the good side than what I have read about most of the MKIIIs. I guess because it was later in the generation. I would do what you need to do. I would not dig ditches in the seams unless you run into some serious voids. You can tell how many defects there will be when you start grinding them down. Some on mine were defect free so I got the seam down enough to add a thin coat of filler. Only the passenger side front fender required more filler due to the slight misalignment of the outer piece which was low. The other fenders were fine. I had most problems with the nose as I am not an expert and required a couple of redos to get it to where I liked the results. HSRF is the way I went. I'm sure I could do a much more efficient job on the second project but that's the way it goes with many first time projects. I actually faired many fiberglass boat hulls for racing but those "curves" do not compare to the body work on the roadster with it's tight radiuses.

Good luck,

WEK.

[Jeff Kleiner]

It's not about how they look but whether gelcoat got into the outermost 'glass layup along the mold parting lines (they are not seams). See the dark lines remaining after the mold flashing has been knocked down with an angle grinder and DA?

http://i269.photobucket.com/albums/jj43/jkleiner/100_0863.jpg

http://i269.photobucket.com/albums/jj43/jkleiner/100_0872.jpg


That's what you need to get rid of. Put a light under the body and it will be easy to see if you have this problem and if you do when it's gone:

http://i269.photobucket.com/albums/jj43/jkleiner/100_0874-1.jpg

The very late Mk3s for the most part did not have as much of an issue with gelcoat in the parting lines as the earlier cars so maybe you go lucky with this one! If not you need to get it out (I use a Dremel with an oval cutter to make a valley) then use the HSRF to restore the strength before moving onto Rage gold.

Good luck,
Jeff

[j.miller]

On Kleiners pic of that 1/4in road of Gelcoat.......The vertical edges of the gel act as fracture lines just like the lines in a sidewalk and over time you'll get two possible things. 1.The paint will picture the gelcoat line. B,Your paint and primer will fracture on one or both sides of the gel line. We use 36gr on angle grinder and or 6in grinder to get to the bottom of the gel then fill with HSRF...da Bat

[stevenburgess]

I picked up the Eastwood fiberglass repair paintucation dvd. It says to respray gel coat once you sand the seams down. This will prevent the mold or seam lines to show thru. The dvd is 120 minutes. I am getting ready to start my body work. It shows all the steps of working with fiberglass, repairs and gel coat.

[Gumball]

Here's a link to my bodywork thread - I did all the bodywork on my Mk3 and it's held up great over the past couple of years. It was painted just over two years ago and still looks as nice as the day it rolled out of the booth.

Doing my own bodywork was not only a great cost-saver, it was probably one of the most rewarding parts of the build as I'd never done it before.

http://thefactoryfiveforum.com/showthread.php?7645-Chris-Bodywork-Thread-Mk3-1&highlight=chris%27+bodywork

Taken last fall just before it went into storage for the past five months - and it came out looking the same....

http://i845.photobucket.com/albums/ab15/CCRsAC/Lake%20Geneva_End%20of%20Season%20Run_Nov%202015_z psvxurvvxx.jpg (http://s845.photobucket.com/user/CCRsAC/media/Lake%20Geneva_End%20of%20Season%20Run_Nov%202015_z psvxurvvxx.jpg.html)