So what's next with this bottom job

[cburger]

Paid a contractor to glass blast boats bottom to bare glass, all gel coat removed. The glass opened up all the blisters some to the size of a pickle. Bottom has a nice roughed up profile that will allow excellent bond to what product gets applied. So upon close inspection there are these lines of small holes that had filler in them. When I discussed this with another Westsail he seems to feel that screws were protruding through the mold when boat was built. You can see that there is evidence of moisture in a lot of theses holes where the filler shrunk.

I am trying to figure out the best way to proceed with getting the hull back in shape, do I have to fill every opened blister, do I have to apply fairing compound over all the exposed glass, or is it sufficient to roll a thickened epoxy, then follow with barrier coat?

[a64pilot]

Well, I’m going to get into trouble saying this, but in my opinion a good thick coat of Epoxy and bottom paint is Airworthy so to speak.
It won’t be pretty, but it would be just as serviceable as if you spend time and fair it out and make it pretty.
She is what, 40 or more years old now? Think if you just painted it how much longer would it be before the hull is structurally compromised?

So fill and fair if you want to make it “right” and pretty, or lay on a thick coat fo Epoxy if all your after is serviceability.

All this my opinion, where is Minaret anyway? Haven’t heard form him lately, but I’d go with what he said if he pops back up.

[Cheechako]

Holes are weird. maybe a PO tried to fix the bottom and aerate/dry the hull by drilling holes...? I agree with A64, fill the holes and any big divots with minimal fairing etc and use real epoxy resin nice and thick. Of course we can't really tell how unfair it is. Wet it and you'll see it all.

[Lepke]

I would fill the holes, dents, with West 404 High Density Filler added to the resin. It has holding properties beyond epoxy alone or any other epoxy filler I have used. Cracks, breaks and other fiberglass repairs I have made with 404 never had to be done again.

[cburger]

Considering Duratec vinlyester products

[Suijin]

I would fill anything deeper than the thickness of a quarter with thickened epoxy. You don’t need to use high density filler as it’s not structural or load bearing, and high density filler is an absolute $&@! to sand.

I would then probably skim coat it with premium marine filler because it cures in 15 mins and is a joy to sand fair. Then I would put on six coats of barrier sand fair again as every imperfection will pop out visually. One more go with the premium filler where you missed spots, fair, one more coat of barrier and then hot coat your antifouling in top of that for the best bond.

You’ve taken it all the way down. Now is your chance to make it right...won’t come again.

[gamayun]

Someone posted about Sail Life the other day and his refit of Athena. I'm infatuated beyond belief at what he's done/is doing. It might give you some ideas -- on how not to go overboard with the project, unless you really want to do something as nice, which is not a bad way to go either Here's his latest posting, which come out each week:

https://www.youtube.com/watch?v=Kjd6Q4NXGEU

[flyingfin]

Get yourself some Awlfair fairing compound, easy to mix, sets up hard and ready to paint in 24 hours. Practice filling and dragging on the big ones first, you will get better as you move along. Grab some nice auto putty blades and you wont have to sand if you work the edges right. Then just hit it with two coats of Interlux Interprotect, then your bottom paint and splash.

[Paul L]

How long has the bottom been left to dry?

[cburger]

The boats been out of the water for a little over two months, most of the he hull is at 15% moisture, plan to let sit until next spring

[gmakhs]

You can fill the holes with fiberglass or thickened fiberglass and finish with vinylester, then apply finishing gelcoat (the one that includes wax to make a nice finish ) or add bottom paint .
You will save a lot of money and vinylester is the way all the modern boats are using on the first layer .

[Suijin]

Originally Posted by gmakhs

You can fill the holes with fiberglass or thickened fiberglass and finish with vinylester, then apply finishing gelcoat (the one that includes wax to make a nice finish ) or add bottom paint .

You will save a lot of money and vinylester is the way all the modern boats are using on the first layer .

There is absolutely no point in regelcoating below the waterline. The only reason it’s there in the first place was that the boat was created in a mold and spraying the whole mold is easy.

Gelcoat absorbs water, which is the whole reason for barrier coating. It also has fairly low adhesion unless it’s hot coated on top (or underneath, in the case of molding) of resin.

He should get the boat reasonably fair with inexpensive, durable, and easy to work with materials, then encapsulate with barrier coat. He could skim coat with epoxy, but it takes some skill and usually multiple people working together.

Sherwin-Williams makes a barrier coat product for commercial marine applications that is probably 30% of the cost of Interlux or Petit products sold by the gallon. You buy part A and part B in two 5 gallon buckets and mix as needed. Enough to give his boat 10 coats and make it bulletproof. That said, the last coat of barrier should be the same brand of whatever antifouling he’s using to ensure compatibility and maximum adhesion.

There are four goals to this process that should be kept in mind when selecting processes and materials for this job:

- fill and fair with durability and good adhesion
- prevent future osmosis
- create a coatings layering system that resists flaking/detachment
- do it as economically (labor and materials) as possible

[Squanderbucks]

It looks like to me some of the holes are open and some still filled. And some are filled with gaps around the outer edges of the previous filler. Depending on how long you plan to keep the boat and what your tolerance for "patch" work is here is what I would do: Test each partially open plug with something like a little flat point screw driver and see if the plug pops out or not. Leave any fully tight plugs in place. Holes with right angle margins are hard to fill without leaving air bubbles down deep and they tend to open back up because the seam doesn't bond well unless beveled. Beveling at least the top edge will give less chance of opening back up visibly. All open holes I would "open up" with a large countersink bit or use a 3M twistlock small diameter disk to bevel the edges and fill each to the surface with good epoxy filler. done right it will only require a small amount of sanding afterwards. Then put 3 to 5 coats of epoxy based hull sealer of any brand you prefer that would be equivalent to the Interlux e-2000. Apply bottom paint as you normally would.

[gmakhs]

Gelcoat protects the fiberglass from.uv radiation and seals it .
But even without the gelcoat the best option is vinylester , there is no reason to use epoxy for 2 simple.reasons.
1 price is redicusly high
2 difference on the material flexibility will cause the bond to brake

[Wind River]

Pressure wash with hot water if possible, repeat each day for the next 9 days or more.

My hull has set peeled for 6 months with small moister meter reductions. After just two pressure washes, my meter reading fell almost the same amount they did after sitting for six months. I have decided to rig up a hot water heater to my pressure washer before continuing with the treatment.

I don't want anyone to have to deal with this again on my boat, especially myself. I am taking the time and money to do it right. It is not for everyone though and I realize that, but pressure washing is within the ability of almost anyone. It make a big difference.

Another reason for pressure washing in your case is to remove the blasting media left on the the hull. You don't want any of the bead left in the layup to create more problems down the road.

This is a great article that will explain what is going on with your hull.
Read it and you will be more enlightened as I was.

http://www.passionforpaint.co.uk/dow...osmosis3v6.pdf