Upside-down Gelcoat work

[Jackman]

I removed the scoops on the intakes of my 32'FB last weekend because they needed cleaning and it was questionable that they may need replaced due to years of use before my ownership. (Apparently someone before me hit something with one of the scoops because a piece is missing.) They were easy to remove...just six small screws that went into the gelcoat and fiberglass. Now that they're removed I can do a good cleaning of the intakes and inspect the shutoff valves a little better.

Anyhow, I noticed that after removal the gelcoat is cracked around the holes where the screws were. Obviously I need to replace the gelcoat. I don't know if someone overtightened them or what but it has to go. I know I have to grind the bad stuff out and put new gelcoat in its place but upside down? I was wondering if the old trick I used to use for body puddying my brothers old ford bronco would work? Put the gelcoat in place and then press on it with wax paper and then tape the wax paper tight against the area that is outside of the area being worked on.

Any suggestions? Special types of gelcoat to use?

 

[TedZ]

That will work but use a release agent and the sheets made for that work. Unless you use an air dry additive or use air dry gel (not common, but certainly available) you must cover it to get it to cure. It is an anaerobic cure product...i.e. the surface is tight to the mold, glass behind.

Ted

 

[Maynard Rupp]

If you mean a little popping of the gelcoat around the threads of a self tapping screw, don't worry. That happens almost every time you initially install a screw. the gel coat is cosmetic and not structural. the fiberglass laminate below the gel coat has all the strength and screw holding power. Gel coat is also brittle and most often cracks as the screw is inserted. the only way I know to avoid that is to spot drill through the gel coat only with a drill that is larger than the OD of the screw threads.

 

[TedZ]

All of the guys i know who mount things on gel coat use a 45 degree chamfer bit after a small bit is pre drilled for location. The chamfer keeps the larger bit from spalling the gel.

Ted

 

[34Hatt]

Gel coat will be fine upside down ( how thick do you want it) also for air dry all you do is add wax or spray pva on top of it. the wax paper will work but overhead might make it difficult. Also you can get gel coat in paste form for touch up.

 

[NAN-PO 41]

If you have questions about fiberglass products contact Joe Merton, of Merton,s Fiberglass Longmeadow Ma. Look them up on the web. Great people to deal with and fair pricing.
No relationship, just a satisfied customer.
Fred

 

[Jackman]

I'm looking at this from the perspective that the cracks around the screw holes are underwater and I don't want to have water intrusion problems...therefore looking to get rid of the cracks by replacing the gelcoat.

 

[luckydave215]

Mix it up, paint it on with a small brush in thin coats. It'll stick in place no problem.
BTW..I worked at the Kettenburgh yard in San Diego as a teenager....doing fiberglass. I got that job based on my experience producing several hundred custom surfboards for a local shop.
I've done enough fiberglass to have learned to hate working with it........itch, itch, itch,

 

[Boatsb]

Clean it. Grind it lightly and coat it with west system or another good epoxy with a bit of thickener. New gelcoat is cosmetic. Epoxy is better for adhesion and water proofing.

 

[bostonhatteras]

Im curious why you would want to use gelcoat at all. first all hatteras' and their exterior parts are PAINTED, second gelcoat is a totally weak material that is so full of pigment it has almost no stuctural strength and third if you do use gelcoat you have to match the color and it most likely wont age well.
why not use west system thickened abit with your choice of filler and paint it?

 

[Jackman]

There is gelcoat on my boat, 1985 32' FB. The place I wish to repair is near the intakes for the engine. I don't care about color matching...I just want to seal it properly so the fiberglass does not take on water. I could use the West system...I was asking for possible choices, the reason for this post.

 

[34Hatt]

Hey Jackan
Being under water changes everything as Scott boatsb said Do it with West system, better and easier.

 

[Boatsb]

And be easy on the grinding. There is no reason to tear it up much. Just get the lose stuff off and the cracks cleared out.

 

[OVERSPRAY]

Im curious why you would want to use gelcoat at all. first all hatteras' and their exterior parts are PAINTED, second gelcoat is a totally weak material that is so full of pigment it has almost no stuctural strength and third if you do use gelcoat you have to match the color and it most likely wont age well.
why not use west system thickened abit with your choice of filler and paint it?

True, they are painted on exterior but they came out of the mold in gellcote. So any repairs should incorporate the same meathods. Yes epoxy will stick but it introduces a product that was not used in the manufacturing. I have uncovered several epoxy repairs during the striping of my hull and to my knowledge none have failed but I still go back with polyester resin and gell for anything I do. Gellcote is by no means a weak material. It doesn't have structural strenth. but it niether does epoxy without glass. I stripped my boat odwn to bare glass and gell and re-applied Gellcote from the keel to the rub rail (pics to follow) It may not hold a gloss as long as paint but it wont scratch as easy either. try dropping a wrench on a gellcoted surface v/s a painted one.Also there are gloss and blending additives now that make repairability and color blending much easier. For the repair you speak of I would chip away the cracked gell, feather-edge and re-apply with a brush and bock sand flat when dry. sounds like a 45 min project to me. Don't forget sanding additive or it will gum up the sand paper. I use a metal countersink when drilling for fasteners to bevel the pilot hole to avoid the edge cracking when puting a new screw in.

 

[bostonhatteras]

Overspray, I'm wondering why you are so enamored of gelcoat. the gelcoat on hatteras' is THE PRIMARY REASON why they blister so badly below and above the waterline. gelcoat is first and foremost a mold release, second it was devised to contain color so manufacturers could eliminate a production step. read the book 'heart of glass'. there are many reasons to deviate from the original production schedule, epoxy has a far more tenacious grip on prepared surfaces than any type of polyester and it doesn't admit water as much as polyester. the technology today, with advanced resins and fabrics is probably the single best reason, for me anyway, to deviate from the original lay up schdule when conducting repairs. the Gougeon Bros/west system manuals are an excellent tech read. by the way polyester does not stick to epoxy, but epoxy sticks just fine to polyester.

 

[OVERSPRAY]

There are several reasons why i choose to repair with gell rather than epoxy, or paint. First and foremost I have the space, time, and experience to take all surfaces down to the the base gell. Yes the gell is a mold release and it eliminates the step of color coating in the manufacturing process. But the primary reason for delamination above and below, Hmm not sure about that one. I will obtain and read the "heart of glass" book. But its no secret that gellcote is tougher than paint. I still think it will withstand more abuse than any other finish coating. I have used many coatings on various projects marine and otherwise, when repairing a gelled surface I stick with gell. if repairing a painted surface I paint. underwater is a whole different story because most boats are bottom painted so the options are broad. I undoubtedly will have one of the only hatteras boats in existence with a shiney gellcoated bottom lift kept in the back yard. I had the opportunity to bring it back to smooth and I ran with it. We shall see what it looks like in 10 years compared to paint.

 

[bostonhatteras]

Overspray
I have to compliment you on all the hard work you have obviously put into your boat. each and every boat represented on this site is one mans pride and joy. do it the way you feel is best and then go out and enjoy it. that's what counts.

 

[Boatsb]

Just a FYI.

Gelcoat is not as hard or durable as Awlgrip or Imron. That is the reason Hatts are painted from the beginning. Polyester in inferior to epoxy in bonding and durability. Gelcoat is a thick layer of colored polyester resin that is designed to be the outer protective layer of the lamination in lieu of paint. It is designed to hold back the patterns of the roving as it dries too. It is not the ultimate underwater substance.

If its below the water use the epoxy to be safe. Thats why the bottoms are coated with West system or other high quality epoxy systems to block water and blistering.

Leave the gelcoat repait to the above water areas as cosmetics. It will be the best way to care for the vessel.

 

[Maynard Rupp]

Just a FYI.

Gelcoat is not as hard or durable as Awlgrip or Imron. That is the reason Hatts are painted from the beginning. Polyester in inferior to epoxy in bonding and durability. Gelcoat is a thick layer of colored polyester resin that is designed to be the outer protective layer of the lamination in lieu of paint. It is designed to hold back the patterns of the roving as it dries too. It is not the ultimate underwater substance.

If its below the water use the epoxy to be safe. Thats why the bottoms are coated with West system or other high quality epoxy systems to block water and blistering.

Leave the gelcoat repait to the above water areas as cosmetics. It will be the best way to care for the vessel.

Ah...There is one exception. I do beleive the original post refers to a 32' Hat. These boats were delivered with gelcoat only. I am told it was an attempt to hold down the price. All other Hats were painted, but not the 32 footer.

 

[Boatsb]

I did not know the 32 was unpainted. That being said I still stand by the statements as gelcoat is inferior to good quality epoxy in almost every way that matters here.