Gelcoat Repair - Need Advice

[NeedOne]

Hey Fellas, wanted to see if you could provide some pointers on Gelcoat repair work.

Using Evercoat Neutral Gel Paste, trying to repair white areas. pics attached of prepped repair areas

1st problem - I will smear out pre-catylist color swatches on a test area until color is 'right'
estimated 3-5% white pigment + 0.1% yellow pigment
When MEK is mixed in, the color seems to change and bias to slightly more yellowish, ruining color match

2nd - It is finishing semi-transparent..
When hardened you can see the dark colored filler/ fiberglass gradient behind it. looks terrible.
The gel paste states no more than 5% pigment

3rd - Finish - I was expecting to lay the gel in a spot, flatten out with acetate film and get a flat almost perfect repair.
Instead it is yielding a 1 - 2mm raised smudge around the repair with pin hole bubbles, smeared gelcoat around from it smashing out of the film..just not a good result

I'd appreciate any advice ..thanks

[XstreamVking]

When the filler is added you will never get the right color or a pin hole free finish. Using a thickened gell coat lighter than the surface color fill the depression slightly lower than the surrounding area. Sand and clean up the filler after it hardens. 150 grit dry. Using just a straight gell cote material fill the surface slightly higher than the surrounding surface. (gell will shrink some) After this hardens sand/blend the area with a flat sanding block and 400 grit wet paper. Try not to go thru the top coat of gell into the filler material. Or go thru the surrounding original surface. Follow up with some 1000 grit wet paper. Buff with some compound and see if the color matches and the scratches are gone. If not the right color, sand back down to the filler and re formulate and try again. I did this job for 30 + yrs and it is tough to get perfect results on the 1st try. A lighter patch stands out less than a darker one, so go lighter. Also sometimes spraying a whole panel is required for a good blend. But that is a bigger procedure. You might be able to get some color matched gell from the mfg, of have some made by a place that does color matching.

[outasite]

You can rent the color chart from fiber glast for ten bucks,you get it back when you return it.Well worth the time to get a factory pack gel,much easier to work with and you can duplicate the color if needed.

[JPEROG]

When the filler is added you will never get the right color or a pin hole free finish. Using a thickened gell coat lighter than the surface color fill the depression slightly lower than the surrounding area. Sand and clean up the filler after it hardens. 150 grit dry. Using just a straight gell cote material fill the surface slightly higher than the surrounding surface. (gell will shrink some) After this hardens sand/blend the area with a flat sanding block and 400 grit wet paper. Try not to go thru the top coat of gell into the filler material. Or go thru the surrounding original surface. Follow up with some 1000 grit wet paper. Buff with some compound and see if the color matches and the scratches are gone. If not the right color, sand back down to the filler and re formulate and try again. I did this job for 30 + yrs and it is tough to get perfect results on the 1st try. A lighter patch stands out less than a darker one, so go lighter. Also sometimes spraying a whole panel is required for a good blend. But that is a bigger procedure. You might be able to get some color matched gell from the mfg, of have some made by a place that does color matching.

Let me know if you feel like coming out of retirement for one last project. I have a really wavy LCB sportdeck that we are about to get started on...
Joe

[NeedOne]

Thanks for the replies

VKing - just to make sure I follow - take two passes with gel ? First to cover dark filler, second on top of that for final finish?
Lighter patch makes sense. will do.

I'm gonna look into the chart outasite, thanks.

Here's an update - another test spot I just finished which will be hidden by the steering boss..

The trace of the fiberglass layup where I faired it out shows through.
I think the dark green filler is showing through too, making it look off color

I'm going to grind these out and test a higher pigment ratio and lighter tone

[tunnels]

Thanks for the replies

VKing - just to make sure I follow - take two passes with gel ? First to cover dark filler, second on top of that for final finish?
Lighter patch makes sense. will do.

I'm gonna look into the chart outasite, thanks.

Here's an update - another test spot I just finished which will be hidden by the steering boss..

The trace of the fiberglass layup where I faired it out shows through.
I think the dark green filler is showing through too, making it look off color

I'm going to grind these out and test a higher pigment ratio and lighter tone

GEL COAT REPAIRS AND COLOUR MATCHING IS AN ART!!
The old gel coat that’s there will have changed colour fromwhat it used to be so even if you had some of the original gel coat that wasused to make the dash It will be a differentshade. Plus
Thetype of catalyst and the percentageused will also change the colouring .
There’s a long list of types of catalyst thatcould have been used, the percentage of catalyst used also has a bearing on allthis as well and will also change the colour !! not forgetting the age of thecatalyst because it loses its potency as it gets older .
Andas for mixing small quantities thinking it will match forget it !! its nevergoing to happen !!
In reality is best to simply fill all and any places thatneed to be filled then spray a coat of waxed gel all over wait till it’s hard thensand and polish ! .
If you arecareful it’s possible to blend the colour differences out over a corner ! ,But nomatter how close the colour match gets the UV in the sun light will change ityet again over a period of time as the new and the old are affected by the UV exposure!! But if you are playing with pigment that's another set of problems Not enough can see through to much and gel coat breaks down very quicklyand powders in the sun !
Have fun and enjoy !

[home made tunnel]

TUNNELS... changing your font to a more elegant style doesn't make you sound any smarter. Just sayin.

[NeedOne]

GEL COAT REPAIRS AND COLOUR MATCHING IS AN ART!!
The old gel coat that’s there will have changed colour fromwhat it used to be so even if you had some of the original gel coat that wasused to make the dash It will be a differentshade. Plus
Thetype of catalyst and the percentageused will also change the colouring .
There’s a long list of types of catalyst thatcould have been used, the percentage of catalyst used also has a bearing on allthis as well and will also change the colour !! not forgetting the age of thecatalyst because it loses its potency as it gets older .
Andas for mixing small quantities thinking it will match forget it !! its nevergoing to happen !!
In reality is best to simply fill all and any places thatneed to be filled then spray a coat of waxed gel all over wait till it’s hard thensand and polish ! .
If you arecareful it’s possible to blend the colour differences out over a corner ! ,But nomatter how close the colour match gets the UV in the sun light will change ityet again over a period of time as the new and the old are affected by the UV exposure!! But if you are playing with pigment that's another set of problems Not enough can see through to much and gel coat breaks down very quicklyand powders in the sun !
Have fun and enjoy !

This really is seeming like more of an art form than any other work I've done on this project...

I think more pigment will improve both of the current issues of too clear and too yellow.
Hopefully I can add more to get those factors dialed in without blowing out the % of mix..
Will report back with next test results

[XstreamVking]

For a white boat I always started with a straight white pre mixed gell and tinted it with some yellow and black to make off whites. Keep trying and you will get the knack of it and soon be able to do it. **When it won't harden anymore you have too much tint** You might get away with 10% pigment, stay with 2% hardener.

[tunnels]

For a white boat I always started with a straight white pre mixed gell and tinted it with some yellow and black to make off whites. Keep trying and you will get the knack of it and soon be able to do it. **When it won't harden anymore you have too much tint** You might get away with 10% pigment, stay with 2% hardener.

Better still is just use a standard coloured gel coat and mask and spray to a masking line along the corner ! or could end up with a disaster !.

[XstreamVking]

I have never seen you agree with anyone on anything. You contradict yourself from post to post. Since I have no time to waste arguing about this and that, back on the ignore list you go......Rail away dude, I don't give a sh.....

[tunnels]

I have never seen you agree with anyone on anything. You contradict yourself from post to post. Since I have no time to waste arguing about this and that, back on the ignore list you go......Rail away dude, I don't give a sh.....

bye !

[JPEROG]

How was he able to vote for Hillary anyway?

Joe

[NeedOne]

Hey big thanks for the help all
Got it done over the last three days
Here's some pics..it ain't perfect but I'm happy with the result

[XstreamVking]

Glad it worked out for ya! It gets better every time you do it....