Blisters

[furball]

Hauled the boat today and found blisters in the hull.
As if hauling isn't depressing enough. I need some information on blisters, this is new to me.
The blisters are spread out, maybe 30 small blisters from bow to stern. The marina manager looked at them and said they weren't "structural" just in the gel coat. Boat is a 2006 and hauled every winter. We pulled the boat at the same yard in early September and I didn't notice them at the time. There are several other spots where all the ablative paint has chipped away and it's exposed gel coat. The back of a small chip I picked off was grey on the back of the red bottom paint so it appears the barrier coat is coming off with the bottom paint. Although I am not the original owner, I have the work order / receipt for the barrier coat that was applied new in 2006 prior to bottom painting by a local yard.
I looking for ideas on how to best identify the cause, fix the damage and be sure it doesn't happen again.
To what extent would you expect the marina that did the original work, to cover the repair and repainting if it is an application issue?
What other issues might cause this if the barrier coat was applied correctly and how would I determine it?
I should have knocked on some wood after that rudder squeak fix that cost 1/2 a cent.
Thanks,
John

[jillsusan]

hi-- i have an 05

had blisters near the bow thruster-- had them sanded down and re glassed fixed-- this year i have found many more all around the hull and keel



i have a blue hull and it has been blotchy for a few years, so i just contracted to have the entire hull re done-- i think it is called imron or emron better than interlux because can be matched better in the future if touch up is needed-- anyway- they will be doing the entire hull so my problem will be eliminated

anyway-- your hull needs to be sanded down completely and re finished the bubbles are in the glass and will take in water you will start to see the gelcoat peel and or crack--not great for the hull -- pls understand i only mean below the waterline for your needs-- i am redoing my entire hull due to the blue hull blotches

you do not need to have the entire hull done at once-- you can have them go after all the blisters and fix them individually and that will be fine. But next year you will find more- so depending on your budget- having it all done is best. find someone who has done it before on high end boats. this is an issue with most boats after a few years the bottoms have to be sanded down to bear glass and re finished (i am not sure what the process is called) it is not just an albin issue.

[Veebyes2]

You did not say if these are above or below waterline blisters. No real matter. If you are doing the job yourself, no real biggie to do, first grind out the blisters. Leave the boat to sit so they can thoroughly dry out. All winter if you want.

Depending on size fill the holes with resin & microballons. Microballoons are available in a couple of sizes. Sand down & finish with fine filler. Prime with a barrier coat & paint.

I have had a few blisters in my Albin & many in my Evans workboat. It is just messy time consuming work.

[Carl]

John, What did you decide to do? After reading this and having my boat pulled the following week, I also found about a dozen small blisters about the size of an eraser head around the bow thruster area. I went back this weekend to look things over, and there is no trace of them anywhere. I think I will do nothing this spring, and have it pulled over the summer to inspect. If they are there then, I will address them at that point.

[furball]

I had the same surveyor who did the pre-sale inspection 2.5 yrs back come up and check the bottom. Since then most if not all of the blisters have disappeared.
What we found, bottom wasn't prepped correctly, if at all, before barrier coat was applied. Barrier coat is nowhere near the correct thickness. Probably one or two coats instead of 5 or 6 coats. We opened 2 blisters and they had some moisture in them but the resin underneath looked good although we opened little more than a pinhole. Measured gelcoat hardness in several places and it measured 43-45 on the "hardness meter" what ever the hell that means but I was told that was good. The hull read good on the moisture meter except for two swim platform bolts in the transom.
So, based on surveyors recommendation, I'm going to prep and paint the bottom, pull the bolts for the swim platform, repair and reinstall then and put her back in the water. There appears to be no structural risk at this point. Keep an eye on it. I have a couple of options. Start chasing blisters each year repairing one by one. At some point, strip or soda blast the bottom to remove paint and open all the blisters at once, repair, barrier coat correctly and repaint.
Put the boat on a lift. I kind of like this idea.
I think the thin barrier coat may be making things worse than having no barrier coat at all. Until I get that removed and done correctly, I think blisters will continue to show up. Lots of good reasons to go to a lift but I have quite a few things to get done to make that work. Marina owner seems willing to discuss it anyway.
Did you have a barrier coat applied when you purchased your 28?

[Carl]

Yes that was part of the deal. I think the same people must have done mine because from what I have seen, mine looks like it only has one or two coats also. Mine has not shown any sign of chipping off or "letting go" but its not very thick. I hope to get over there this weekend and get started on the engine zincs and fuel filters. May even change the trans oil since this is the "every other year" for that. If I get that all done quick enough I will change the coolant, and then all I will have is the outside. I think I will just touch up the bottom paint for now and when I pull it this summer for the bottom cleaning and wax I will decide what to do if the blisters are back. Which 2 bolts on the swim platform are showing moisture? I recall having a couple that seem to be coroding more than the others.

[furball]

Carl,
Moving from port to starboard, #3 and #5. I'm going to pull all 6. I figure they were all done wrong so might as well.
Hoping to spend Sunday doing maintenance as well.
Good luck.
John