Wetsanding Mold Lines - Any Advice?

[Alex]

Getting ready to start wetsanding the mold lines. The only "problem" that makes me nervous is how close they are to the edges of the vehicle.

I guess all I can do is tape off as much as possible infront/behind the mold line, then start hand wetsanding with 400/600/1000/1500/polish, replacing the tape when it starts to move.

Any other tips or tricks to keep in mind before i jump into it :idea:

 

[Randy V]

Gel Coat is very soft

• Go slowly
• Add a few drops of soap per gallon of water as it helps the paper release the material removed from the body
• Use a backer behind the paper so as to distribute the pressure from your fingers evenly across the paper.

Enjoy!

 

[Dave Deerson]

Wear old clothes(it's really messy),and change paper often.Use a guide coat( I use a cheap flat black spray bomb) Let the paper grit do the work-if you have to push harder then the paper is clogged or done. The harder you push, the more likely you are to getting waves in the bodywork.Also sand in diagonal directions and change directions often(puts less scratch marks into the surface that you will have to get out with the next grit).
Open fresh bottle of favorite beverage at each grit change!!!

Dave D.

 

[Trond]

Hi

I find it very helpfull to spray paint a very thin, almost just a dust-like layer of black paint on the body before sanding. This will fill inn all the "holes" in the surface an indicate when you have reached an even surface without ant pores or scratches.

Regards
Trond

 

[Alex]

I did not know about the spray trick; thanks.

 

[Alex]

I must say, the mold lines on the SLC are very impressive.

I'm coming from FFR ..... quality ......, so when Fran told me I could wetsand polish them out and I'd be golden, I figured 'yeaaaa, riiiiiiight'. (again, remember i'm used to seeing mold lines 1/2'' + tall that need to be ground out)

Anyways, started tackling them today and they knock down like crazy.

4-5passes with 1000
10 passes with 1500
10 passes with 2000
finish wth 3000
then pfw+menzerna SIP to remove sanding scratches
white + menzerna 106 for a perfect finish (just as good as paint; i'll post pictures when I'm finished).

Woooooooooo :thumbsup:



Now, only 1 'problem' I''m running into - every so often I get a little spot on the mold lines where (before I start sanding) I can see the fiberglass below (i.e., no gelcoat coloring). So I sand and polish and (obviously) the spot is still there (hasn't grown, so I'm not sanding away too much, heh). The spots are very infrequent, and very very tiny. Maybe like 2-4mm long, 1mm wide (i.e., very very small).

So I'm thinking they will be perfect if I can touch them up (nb: I'm still a gelcoat newbie, so go easy on me). I'm thinking the solution is one of two things

1 - gently dab gelcoat (mixed with mekp, etc...) on the area and wetsand it down

or

2 - take a file or fine dremel bit to the area to hollow the area out, hollow out a little bit, then fill in with gelcoat. (since gelcoat flows into cracks)

I'm thinking #2 is right, but I'm curious if there's a better way.

 

[Trond]

Hi

You will have to go for #2 sulution. Be sure you have the exsact same gelcoat colour to fill in. If you have that you will be able to sand the new gelcoat down to an even and homogen surface equal to the "old" surface around. You will not see the repair at all.

Be shure to do this on an aeria that is lagre enough, so that you not get the same problem you have now on the edges of the fixing point when you sand it down.

Regards
Trond