Destined for Davy Jones? Excessive blisters.

[StoneCrab]

Anything can be repaired.

Patrick Childress has a YouTube channel "Where is Brick House". He has been cruising for twelve years and a year ago hauled out in South Africa to address some boat projects. One being the repair of his hull blisters.

You would benefit from watching his videos on how he did it.

You are on the right track.

It takes commitment and the right attitude...and a lack of fear.

Good luck.

[fred4936]

+1 on Patrick Childress. Valiant 40's had a bad run of blister issues, but they are still great boats. Good luck!

[fatherchronica]

I have bought boats far worse and done the repairs myself and did such nice jobs that 2 surveyors have recommended me clients needing blister repairs. I did not do them as I was already in a business with several employees that was more fun and more lucrative than blister repairs. You can do it. I recommend Progressive Epoxy.

[Mike Banks]

Not all hulls are created equal--especially those built using a chopper gun. Some have errors in the mixing, others included air (hence moisture) at the outset. In time osmosis seems inevitable--

Can it be fixed? Of course it can. Is it WORTH fixing? That depends on the rest of the vessel and the condition of its engine , the rigging, and the rest of the chandlery aboard.

If it were I, I would do as you have done and plane off the gel-coat entirely. Then it needs a light sand blasting, to make obvious any remaining soft spots. Once you can see the hollows, probably with sand particles stuck in them, you can begin digging and raking out the decomposed ill-mixed decomposing mess using shave hooks, chisels, curettes, scrapers, whatever it takes, to get out that soft stinking putty-like crap and any contaminated fibres remaining.

Once that is done, dry them out using a hot air gun. When dry, clean them using acetone.

Now one has to make up an epoxy putty to fill the cavities remaining. This is a time consuming job because it can not be rushed. Each hole is a mini-project, you can only do so many at a time.

I would mark off an area with a spirit based marker pen, such as will dust off afterwards like a white board marker. Do one area at a time probably better to start at the top and work downwards. Brush correctly mixed slow cure (if weather warm) epoxy resin into each cavity, making sure to wet it entirely. Do that to all of the cavities in your marked area--or keep going until you have used up your epoxy. Do not mix too much of it, because your next job is to use the putty--and you have to mix that while the wetting coat takes an initial set-up.

Your putty mix uses varying mixtures of phenolic micro balloons, cabosil, and if you wish, cotton or glass fibres depending on the size of the cavity. I have packed some larger ones with chopped strand mat and allowed that to set up before adding more--eventually finishing with the phenolic micro-balloons and epoxy mix as a final fairing compound. I do not use the much cheaper Q-cells below water line, but they are fine anyplace else. They make sanding the surface easier--so always just use the micro balloons as a fairing putty. The rest has to be strong stuff and it has to stick to the existing sound polyester fibreglass really well. If your hull is a sandwich construction, you will have to replace the core as well, and use a bead mix to fill any voids--then re-glass the surface layers using woven cloth. Such fun!


When you have finished and faired the hull, I would then roll on another layer of biaxial glass cloth, with peel ply over that. Then re-fair that and paint with an epoxy primer, a couple of layers or more of a good UV-resistant polyurethane, two coats of chlorinated rubber barrier coat and then on top of that before launching, one or two coats of hard antifouling followed by two coats of soft ablative antifouling of a different colour. When you see the hull colour changing, book the slip.

Fixing hulls is time consuming and expensive. I know this seems a superfluous statement, but there are no short cuts if you intend going offshore in it. Your life and that of anyone else aboard depends upon your workmanship and the quality of your materials.
.

[Tingum]

I don’t know what you’ve got in it or what your plans are for using it. They were not that well built from day one. You say you have the time. I’d just roll on a couple layers of epoxy, bottom paint it and go sailing.

[canman]

Other than resale being an issue, Are there any factual reports of actual hull failure or sinking due to blistering?

[ferrailleur]

don't despair....
my Catalina 27 was infested with blisters after soda blasting.... I grinded them all, filled them with West System epoxy plus addidive (407?)..... applied 5 coats of Interprotect 2000 and 2 coats of Micron CSC (is that the name?)....
No more blisters.... end of story..... hard work but worth it!

[joelhemington]

Originally Posted by coopec43

You might be interested in reading these articles by a well known surveyor.

Boats, Yachts: The Wonderful World of Hull Blistering

https://www.yachtsurvey.com/BlisterFail2.htm

https://www.google.com/search?ei=RnW...YGMCKoQ4dUDCAs

Great post!!!

I found it particularly interesting that a boat 5 years or older with no blisters would probably never get one. Had no idea about stranded mat and why you don't sand blast. My overall take away is only buy a boat made by an accredited builder that only makes their boats - not some builder that does a series of knock offs of various designs (Shionning comes to mind). Clearly product quality and consistency in production makes a difference here. I think I would avoid blister boats going forward as it clearly indicates a substandard hull (both in construction and the materials used )