8 years since the last bottom job.....

[David Underwood]

Wow, I just love the way she looks in the yard. Makes her look twice as large as she really is. Hunter 33 shoal draft in the yard and ready for bottom job to be done by yours truly. Guess I just wanted to share this view of her with other 33 owners. The other thing is she does have some blisters. I think about 12 or so are fairly large ... say 1 to 2 inches in diameter and most everything else is under 3/4 inch in diameter. My plan is to pop the larger ones with a grinder and let them bleed while I sand the others to open them with less aggressive means. Since its been 8 years since I last did all this, has there been any new products that I should be aware of to make a better repair to the areas I have to grind out or should I just plan on using epoxy with thickener additive to fill in the blister areas. Comments by others in the yard was it did not look too bad for a boat with an 8 year old bottom job. Anyway, just thought I would throw this out there to see what comes up. I just dread doing the dirty work, can't afford to pay price of having it done for me. Thanks for any advise, I'm always listening and learning. O, and also thinking about replacing all thru hulls while I'm at it. Suggestions there too would be great. Thanks!

 

[Doug T.]

Delamination

I'm not even going to try to give recommendations on how to "properly" repair blisters -- there are far too many opinions to go around on that particular subject.However, just wanted to make a suggestion: Get yourself a small hammer and tap-tap-tap every inch of the hull. Start with an area that's obviously sound at the bow and work your way up and down the hull, moving slowly backwards. Pay special attention to the areas around any blisters. If there is any delamination in the fiberglass layers it'll make a distinctive clicking/clacking sound. Delamination is a bad thing -- it seriously weakens the strength of the hull.I bring this up because we used to have a '77 Hunter 27. We knew it had blisters when we bought it, but figured we could fix them. After starting work we discovered that underneath the paint and gelcoat the situation was far, far worse than we ever could've imagined. OK, so the blisters were repairable -- maybe -- but after tapping around with the hammer we found that there were large areas of the hull where the fiberglass was completely delaminated. (Listening closely, you could actually even hear the difference between two-layer delamination and three-/four-/more-layer delamination!) Small areas of delamination you might ignore or repair by injecting epoxy. Large areas are seriously unsafe and require the wholesale application of more layers of fiberglass over the hull. Not cheap.

 

[Ed Schenck]

Wow, those Cherubinis are. . .

good lookin' boats! Are you out of the water right now? And do you have to hurry back in? You did not state what kind of a bottom job you did eight years ago. Did it include a barrier coat?If you are just going to bottom paint then what you plan is still what is recommended. And if you are seeing some blisters after 8 years the moisture is already in there. So I don't think a barrier coat would be much help. It is not very expensive however but it is a whole lot of work. If you have the time and energy it will slow the blistering. I put six heavy coats on my '79 H37C after taking the bottom down to gelcoat. And with a scraper and a sander. The last two haulouts the bottom looked brand new.

 

[Steve]

fix it right

I just did mine this year, had a few blisters too. If you got blisters, take the time and expense to fix it right now so they don't come back. Your going to need to dry them out good, clean it good, apply special expoxy for blisters, fair them with epoxy filler. Strip your whole bottom, apply a barrier coat, actually several barrier coats, then rebottom paint. Check out the InterLux web site, they have instructions and products to handle it. You may find more blisters after you strip the bottom paint off, I did. Some of them are not obvious with the bottom paint on. Good luck, and don't skimp on this if you plan to keep the boat. Oh, and wear lots of protection while doing this. Respirator, gloves, eye protection, full body suit.

 

[David Underwood]

I'm heading up today, with hammer and grinder....

to check it out. We pulled her two days ago and I have not been able to get back til now.. weather has been cool but been too busy with work. Anyway, going to tap out the hull and listen, then, hopefully, with no delamination, I'll proceed to grind out the larger ones and get them draining. The yard price for self working is $11 a day for the first 14, then it goes up sharply to $22 per day. So, hopefully I get it all done within the 14 days... so I'm praying all the way to the lake. Will let you know what I find.. thanks everyone, keep the suggestions coming since it will be work in progress for a couple of weeks. thanks again.

 

[Pat McCartin]

thru-hull's

David,When I did mine 2 years age I replaced all the thru-hull's AND backing plates. The original barkers are ply wood and most of mine were rotten. I wen't to the machine shop nd cut pieces of Delrin for the new backers and bed them with 5200. No leaks yet!! I also did the strut this way, not shure how your's is mountedPat McCartin1979 H30 "Thereapy"Lake Lanier, GA

 

[Sam Lust]

Lots of "IF'S"

If you have blisters, you have water invading the layers of fiberglass/polyester resin lay-up. That MUST be dried up before sealing with barrier coat. Barrier coat in that case would seal In the water with no way out but into the bilge, which it has been known to do, or elsewhere on the surface. The drying process, done correctly takes MONTHS. Check it very carefully. If you don't want to take the time now to dry it right, just repair the damage, give it one coat of ablative pailn and drop it in the water. Do the job right when you have the time. That's what winters are good for up here in the Noth East.For the record, I sand blasted my 1983 Hunter 33 and for reasons I don't understand, found no blisters at all. Pure chance, or Hunte had a good day the day they laid up my hull. Gave the hull several months to dry and sprayed on about .030" of interlux Interprotect. I don't forsee any problems.

 

[David Underwood]

What I am finding.... and Sam, please comment further

Went up yesterday and tapped out the hull with a small hammer. Most blisters just spit at me and everything sounded the same except a couple of the ones that were the largest, about the diameter of a golf ball. These larger ones when tappped were deeper, I could hear it and when tapping they began to open up to a depth of about a 1/8 inch. I then took my grinder and began to explore these, removing gelcoat and getting into the glass using shallow grinding and found that I could see where the glass was beginning to come apart in the first layer of laminate. As I moved out in all directions, I ended up with an area of about 4 inches in diameter before everything was connected again. Seems just the first layer was affected and was solid out to the outer edges of the grinded area.Just as a side note... I did this kind of repair 8 years ago, on the port side mostly, and the area where I removed glass til solid and repaired with Marine Tex... a two part expoxy mix .. worked. That area has hardly any blisters at all. The area seems very solid. Also I should mention, about 13 years ago, I had done the blister repair and barrier coat job. I don't have time to dry her out properly right now. So Sam, should I use epoxy to repair area after I get them to solid glass and NOT do any kind of barrier coating to replace what is sanded away on this job? Or should I use regular polyester glass and cloth to fill these voids and then just fair them out with a fairing compound?Anyway, thanks every one, please keep the advise coming.

 

[Steve Dion]

Some schools of thought say leave them open.

David:If you check out the archives there was a list of articles I found on the internet. One of them suggested you open them up (the tend to be acidic) and just paint the bottom (no repair)Check it out for yourself.http://archive.sailboatowners.com/archive/archivepview.tpl?sku=2001303062929.82&forumabr=as&fno=122&_ptitle=ptitle%20rtitle&_pname=pname&&model=none&forum=none&andor=wa&keyword=blister%20dion&pr=p&ssite=HOW&srt=pdate&start=1&max=20

 

[Jim WIllis]

Childs Guide to blisters etc on Gelcoat & Plastics

..Froum. This is posted on the gelcoat and plastics forum (why does nobody ask about vinyl or hypalon? etc).This is Fiberglass Trilogy Number III.It is an amalgam of written reports, my own and friends experiences.ThanksJim W

 

[David Underwood]

Thanks everyone, she is still drying, but looking

pretty good. Seems pretty dry where I ground out he blisters, watching for any that seem to continue to weep. Going to dry her for as long as I have and then make repairs. Thank you to each and everyone that replied. Dealing with other issues also, so plenty to do this haul out. Some way to spend vacation. But I do love my boat. David UnderwoodS/V Freebird