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After priming and painting the bottom of the hull of my Malahini, I was doing a final inspection of the sides of the hull prior to painting and notices along a part of the top edge of the boat (bottom as it sits upside down) that there is an area where 8 screws that we're filled with fairing compound are now popping up above the surface of the boat. Looks like when a drywall screw starts to pop up out of the drywall. Don't know why it has occurred, but don't know what I should do about it prior to painting.
My guess is to sand it flush and hope I don't end up exposing the screw head. Anyone have this problem ? Help?

I'm absolutely no expert on that particular problem because it hasn't happened to me. I've also noticed that several people that I would have thought would know, have posted since you started this thread and they've not responded to your question. So maybe they don't know either.

So here's what I would do. I would take an exacto knife or pocket knife and just start digging at one of them to try and get an idea of how much adhesion you've got. In fact, I'd go ahead and just dig one of them out. If it's a real bear to dig out, I'd sand them all flat and paint away. But if it comes out pretty easily, I'd bite the bullet, dig them all out and do them over. That may not be the answer you want to hear but I think you'd be happier over all.

BTW, I don't know what other builders are doing but, anytime I have had to sink screws in the hull, I dabbed a little epoxy in the hole before I put the screw in. After that, there sure isn't any worry about the screw backing out. I think that it's the screw working around that may be the culprit.

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Isn't it amazing!! The person that never has the fortitude to pursue his own dreams, will be the first to try and discourage you from pursuing yours.

Thanks for your response. I sanded everything flush and reprimed. I think the reason these 8 screw pops happened may have something to do with a space heater that was located just a couple of feet away from the location of the problem. The heater has a fan and I think that area of the boat was getting fairly warm. It has not occured anywhere else. I moved the heater further away. I am working in a one car garage - pretty minimal space. Didn't know it might cause a problem.
If anyone knows that this was the cause of the problem please respond.

I've heard of that happening to a few folks on here,but don't remember what the cause was or how they repaired it(or if they did).

_________________
Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

My "GUESS" is something is forcing the plug up.
Better dig at least one out an see if a Chemical action or maybe a physical stress of some kind is the culprit.

In drywall its usually because the screw want set properly. The drywall wasnt firm against the stud when it was attached. In this case I suspect you are right about the uneven heat.

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John Amundsen
Monte Carlo
Winter Haven, FL

Maybe it will be done by G6 and maybe not.

Please tell us the filler type that you used. What type of primer? Fiberglass? I may have missed all the particulars. But for the sake of having the particulars listed on this thread, I think it will help me anyway. If you used epoxy as the glue for your application of the wood, I doubt that you have the fasteners popping up unless from the very beginning you did not have the fasteners counterbored and sunk enough.

I'm more sure that this problem was due to the heat from my heater being too close to the boat. The popping got less noticable the further away from the heater. The fairing compound I used was Quick Fair and the epoxy West Systems, and the primer was from SuperMarine paint.
Maybe someone can explain why heat caused the fairing compound to expand? Is that what happend?

Maybe metal screws expanded at a different rate under heat than the surrounding wood did?

Just a a guess.

You did glass cloth over didn't you?although on at least one boats with popped screw fills I know,it was glassed over too.

_________________
Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

Read up on shrinkage of epoxy pertaining to the viscosity. But also over time in new applications the natural curing process causes some shkinkage too, which is highlighted in certain temperature changes. In the wintertime and for hulls that were going to get darker colors as a topcoat finish and was built using laminated planks in multiple layers, we would actually move the small hulls to a sunny side of the building outside for a couple of days to allow time for the epoxy to post cure. Fairing compounds blended with epoxy and used over the heads of fasteners as a filler also shrinks more disproportionately than surrounding glassed areas too.

Yes, the boat was glassed over.

A little confused - the fairing compound seems to have expanded versus shrunk - due to heat? Unless it has something to do with the screws getting hot under the fairing compound too.

No the epoxy surrounding the non epoxy filler shrunk.

Man up boy?
Take at' hole mess outside n' work in the Snow like the rest of us.
Then we'd know what the problem is from experience!

Best thing about working in the Wyoming winter is that you can apply your glass and epoxy and then if you arent happy with it a week or two later you can simply peel it back and re-apply, once you think you have it exactly the way you want it you can put some heat to it and let it cure..or wait till spring!

Steve