To paint or not to paint?...that is the question.

I recently bought a 1969 Scot and have flipped it over and sanded off all the antifouling layers off with an orbital sander.  Quite a time consuming job, i might add.   Suprisingly, the gelcoat is in good shape for its age, with some minor spider cracks here and there and a few dings that are not terribly deep, but where the gelcoat is off where i can see the fibers in the fiberglass.  The biggest one is about 1/2''x2" or so.  No blisters.The boat will be dry sailed.  Do I need to do anything other than repair the dings?  I was going to just re-gelcoat the dings. I first thought of using an epoxy filler, but then i was told that if I ever want to gelcoat the bottom, the gelcoat will not stick to the epoxy areas. Can i just sail it without any barrier paint such as Interlux 2000E?  I hate to paint it since this requires more work and upkeep, but i am concerned about water penetration.  Also, it will be faster in the water with no paint.I have read opposing views on this subject.  Any opinions are greatly appreciated!Thanks!Inge  #1456

I totally agree. Paint is for boats where the gelcoat is not repairable. The sequence described is right on the money.

The sanding is a sequence of 600 then 1000 then 1500, all done wet, in the direction of water flow, front to back.

A good professional auto body supply shop is the source for good sandpapers in these grits.

Phil Scheetz
FS 4086

Thanks for your reply, Phil.  You confirmed my thoughts, which makes me more confident moving forward with my plans for the bottom.  Also, thanks for the tip on sanding the gelcoat.  It would not have occured to me to sand in the directions of the water flow, but makes sense.I have applied gelcoat on a few spots.  Althought i match the color well, after sanding, it is not perfect and there are a few imperfections remaining.  Can i apply another, thinner layer on top of the newly sanded gelcoat layer that i just applied to get a better finished top coat?  Will it adhear or do I only have one chance to get it right?Thanks again! This is hard work, but rewarding at the same time and i am learning a lot in the process! Inge#1456

West Marine has tested the claim that gelcoat will not stick to epoxy resin: see  They find that it adheres just fine.  Of course, it would be in their interest to find exactly that but I have not seen any tests to dispute their finding.  I have been having very much the same thoughts as you, except that I do not plan to race my Scot and plan to paint it because I (think I will) like the look better. I had been going around and around on the gelcoat over epoxy question until I saw the WM test results. I now plan to fill my dings and spider cracks on the bottom with epoxy (and then paint) because I believe the epoxy will seal better and fill the cracks better.  Hope I'm right.  I'd be glad to hear otherwise from someone with more experience than I have...which would be pretty much everyone.

You can add another layer of gelcoat.  You might consider adding come "cabosil" filler to the gelcoat mixture to thicken it up.  It makes it much easier to work with and the stuff isn't running all over the place

West System Epoxies come from a company called Gugeon Brothers. (spelling?) While you can buy it at West Marine, it is not made by them. It was always my impression that a gelcoat over polyester bond was slightly stronger. In either case sanding the repair area with rough sandpaper will promote mechanical bonding.

Why not just do all your filling with poly gelcoat? It is easier sanding than epoxy. Some epoxies are harder than gelcoat and thus hard to get really fair with the surrounding gelcoat.


 Interesting about the West System products.  I think that is what i will do... fill with poly gelcoat.  I think I will give it a try, then i can asess over the summer  and again at the end of the season to see how they are holding up.My main concern is still water pentitration, but since we are dry sailing the boat that should not be an issue, correct?Also, should i worry about spider cracks on the bottom in the gelcoat? There are some spots here and there, not all over and do not seem to be too bad.Thanks again for your guidance.Inge