Doing my own gelcoating

[Eric Swift]

On my old boat, after some damage done by a piling, I ventured into doing my own gel coat repair. I used disposable spry units (WM) and first matched color and then added catalyst in small batches before spraying. I sprayed a coat of mold release over the gel coat to promote hardening. I found this process easy and it yielded a nice buildup of new gel coat that I could sand down to feather it in and in the end yielded a nice repair. What I am wondering is why this is not done more by us "do it yourselfers" and if there is something I am missing that would suggest going to Awl Grip or other finishes would be better. I am thinking on my H34 of re-gelcoating the entire top sides to restore the finish and cover the multitude of scratches etc. It seems to me that if the surfaces are prepared well, new gel coat would be the surface of choice because of its workability and because it is the same material already in place. Please advise.

 

[Jim Willis]

Absolutely Right!

Gelcoat repairs really only have one difficulty- color matching. But if you are careful and "blend" it will not be noticeable - can even do a whole area easily. See Gelcoat Trilogy II (posted above on this page in yellow) for hints on color matching.The trouble with painting over gelcoat is usually:1. Expense A profesional job is expensive and not worth doing for minor blemishes.2. Adhesion. Because older gelcoat is porous and has wax imbeded in it, extreme care has to be taken in sanding down a long wayinto the gelcoat, degreasing/dewaxing, priming and painting. This is not true (say) of a car paintjob where the substrate is not porous and very thin. By contrast, a gelcoat repair involved partially meling the underlying surface that then forms a tight chemical bond between old and new - and dissolved wax can float to the surface and actually add to the gloss as actually done deliberately in some cases (see Trilogy II)3. Repairability. The LPU surface, although more durable, is much thinner than gelcoat. You can't do much polishing without going through, not can you sanding and polish out minor scratches. Some urethanes (imron) are difficulat to "feather edge". Getting a gouge in an LPU surface is a major heart ache especially with that brilliant shine showing every little defect!By contrast Gelcoat is really soft to sand and polish- LPU is not. It is also thick enough to take abrasive restoration where unavoidable (e.g. dicoloration of surface layer of pigment, excessive surface roughness).4. Skill level and color matching. repairs and resprays with (have done myself as I repaint and restore cars) is not easy to do. By contrast, even if you "screw up" a gelcoat repair and get runs etc its easy to sand and polish smooth or even redo if you don't like it.etc etc - I do go on don't I?ThanksJim Willis

 

[Bill O'Donovan]

Jim got it right

You casually mention that you matched the color, but Jim points out that is the great difficulty in gelcoating. Any given boat has up to a dozen shades of white depending on where the problem is on the boat. If you have mastered the color angle, you have yourself a cottage industry in the future. Congrats.

 

[Eric Swift]

Well.......!

In saying I matched the color, it was relative and compared to a hole that showed the glass, the repair was great. On the other hand, the patch could be seen when viewed in the right light and from the right angle. It was interesting to see how the color of the old gel coat would appear different in different light and from different angles. I agree that matching is not easy. The transom I did was much easier since I did the whole transom. Hence my interest in doing the whole hull above the water line. Thanks for the help.

 

[Eric Swift]

Well.......!

In saying I matched the color, it was relative and compared to a hole that showed the glass, the repair was great. On the other hand, the patch could be seen when viewed in the right light and from the right angle. It was interesting to see how the color of the old gel coat would appear different in different light and from different angles. I agree that matching is not easy. The transom I did was much easier since I did the whole transom. Hence my interest in doing the whole hull above the water line. Thanks for the help.