Bottom Questions

[Glory]

It's a big job, I did my bottom about 6 years ago. repaired the blisters and 2 coats of epoxy two colors of bottom paint.

Pros, save a fist ful of money.

Cons, like most jobs on the boat over budget on time.

JM

[jim rosenthal]

DON'T peel the bottom. Blast it clean, let it dry THOROUGHLY- this takes weeks if not months- and then fill the blisters with VC Watertite or some similar fairing compound, and recoat the bottom with InterProtect or equivalent barrier coat. While it is tacky, roll on your bottom paint.

Blue Note's bottom was done thirteen or more years ago with this system and has held up very well. When (several years ago) she was at Slane Marine for her Cummins engines to be installed, they had the bottom cleaned up with soda or dry ice blasting, I forget which, and it was all holding up beautifully. They rolled on two or three more coats of IP and repainted her. She is still doing fine.

Very few boat bottoms need peeling. It raises the costs considerably and makes the project take a great deal longer than it needs to, depriving you of the use of your boat for even longer. It also can compromise the bottom structurally depending on who does it and how experienced and careful they are with your boat. Don't peel it. Save some money and just blast it, dry it, fair it and recoat it. That will serve you just fine, and your boat will love you for it.

[saltshaker]

What does the bottom look like now that she's been blasted? If you have a lot of open blisters, the longer you can dry them out the better. Talk to the yard and see what they recommend since they are the ones doing the job. You could drape the hull and put dehumidifiers under the boat to help the process. This is much more effective if indoors and/or on pavement or concrete. It's crucial that you get it dry and properly sealed up. Blisters on a Hatt typically aren't an issue if left alone. Once opened up they have to be properly repaired or you will end up with a problem.

[luckydave215]

I went through this same thing, soda blasting to remove a million coats of paint opened up a bunch of (otherwise tiny non-issue) blisters.
We ground them out, filled, barrier coated and painted. All the water in those blisters was confined to the blister itself, spot grinding ~1/16" deeper took care of them.
That was three or four years ago, at last haul not a single blister was found.
DON'T PEEL THE HULL, you'll regret it.

[bobk]

I wonder why all the advice to not peel a bottom.

I bought a brand new Albin in 1986 and applied Interprotect before putting the boat into service (yes the mold release was removed). I had many blisters after the first season as did many other Interprotect users. The advice at the time was to let them 'ripen' a few years and they eventually found their way through the veil layer. I had the bottom peeled just enough to remove all the veil layer, dried it out doors in MD over a winter and I faired and built the barrier back using Vinyl Ester resin. I sold that boat in 2006 when I bought the 48MY. No blisters. VE is harder to use than epoxy, but it sure is a better barrier and worth the effort. Sorry, I digress.

Bobk
1981 48MY
Chateau de Mer

[rwappleton]

The bottom was blasted with wet glass. As I stated earlier we are in no rush. Mid march was our earliest launch date. She is on concrete in Charleston so humidity should not be a problem until April or may.

There are maybe 200 that have been repaired that are holding up well. Maybe 60 that reblistered. Deepest is maybe 1/4" and 99% just gel coat. Another 200 new ones all very minor.

I have pictures I am going try to download to tonight for further review. I decided against peeling before we started and it seems to me the barrier process HAS to be done precisely.

[Vincentc]

About 25 years ago we removed blisters on a 43 Gulfstar. Some of the blisters were the size of half an orange. I used a sharp paring knife to carve out the blisters using a circular motion and got pretty good at it after a few hundred times. There was an impressive amount of water inside that smelled of vinegar.

Drying takes a while.

After the knife I used a large grinder sander. i applied a coat o epoxy the while the epoxy was still green, followed with filled epoxy in the depressions. i used the grinder sander to fair things then two coats of epoxy.

It was a big job, and I had more energy then. Not sure what I would do now, but I wold definitely hire some workers.

I would also tent the bottom and use some dehumidifiers. May be a month to let things dry out.

I recently had good result applying bottom paint to epoxy on the shafts that was not fully cured.

Regards

[jim rosenthal]

I can't speak to this problem on other makes of boats. I haven't owned any other fiberglass boats. But the leading authority on refits of older Hatteras yachts, no less, strongly recommended against peeling the bottom, and I followed his advice. And I've not been sorry. I am not familiar with the laminate schedule on Albins, and I would not presume to give advice on what to do with a blistered Albin.

[Boatsb]

I can't speak to this problem on other makes of boats. I haven't owned any other fiberglass boats. But the leading authority on refits of older Hatteras yachts, no less, strongly recommended against peeling the bottom, and I followed his advice. And I've not been sorry. I am not familiar with the laminate schedule on Albins, and I would not presume to give advice on what to do with a blistered Albin.

Jim I have seen both peeled and blasted Hatteras repaired beautifully and to be fair each one was done because that was the best method for the damage. Other boats have similar issued and I have repaired blisters on dozens of boats over the years. While I think peeling is extreme it is sometimes necessary to get to a stable base. Baths do not usually need such a radical method but sometimes they are just that badly blistered.


By the way interprotect is jot a bad product when used properly. Too many people do not get enough buildup because of thinning, sanding or other mistakes. Most coats of interprotect dry far thiner that you may expect. 6 coats is usually my minimum as it gets thinned here in Florida to make application easier.

[Glory]

I see several questions about drying out the bottom after the prep is complete. This is a troubling issue in the NE, shorter boating season so you don't want to do the job in MAY, and it's cold in most if the off season. To remedy this I tented the bottom , from the boot stripe down, and on weekends while I worked on the other things on my list I let a kerosene heater with a box fan moving the air around under the boat run. Each day i used a moisture meter on a spot marked on the bottom, same spot every time, and it seemed to help. Any space type heater should work fine if you are fighting below freezing temps. in a visit to the boat one night i found an icicle hanging down from on of ground out blisters. I ground the area further and could not find any additional moisture.

When grinding out a blister , I used a dremmel tool ( several dremmel tools on the thousands of blisters, several hundred on the port and thousands on the starboard side) you grind into the blister and the carbide blade has a rooster tail of foul water, once past the moisture the grinding delivers dust, and days later some grinding sites are wet again. After using the above heat I managed to get past this.

My orignal reason for tenting off the hull was to prevent rain from running down the hull into the the many grinding sites, it turned to even more helpful for the drying process. As I indacated in an above post this is a time consuming and messy project, not the kind your criusing or fishing buddies will rush to help with.


JM