Blisters!

[Dave Mason]

What to do about blisters? They are in line with the ballast tanks above. I waxed over them while I was doing the topsides, but is this enough? What are the remedies, if any?
Thanks, Dave Mason, '01 26X

[c130king]

Dave,

Found this when I did a search on "blisters".

Blisters

Found 43 topics. Looks like a few of them will give you some answers.

Good Luck,
Jim

[Russ]

I plan on leaving them alone. I don't see the value in sanding and patching and all that. Some bumps... so is life.

[dutchwinter]

dont they grow and delaminate the hull? We know someone who bought a used trawler and they put her up on stantions and had to sand down, and build up the whole bottom becasue it was neglected for so long. the issue was blitsters and delamination. the cost was significant, even though they did all the work themselves, and as a liveabord, even worse. though now that its all done they live a beautifl lil spot at Cappelle aan de ijssel. anyhow, blisters are my biggest fear maintenance wise.

[daydreamerbob]

i think it is sh~t that we have to deal with this; but some of us do. There is no doubt that there is/was something wrong in the layup process for some of our boats - but my belief is - there is nothing the factory will do to help. Anyway - my dealer addressed the issue last year - will pull the boat and evaluate the success of his work at the end of this week. I am not the most experienced boater - but blistering - that covers wide areas of the hull - need to be addressed in an immediate and urgent manner.

[Divecoz]

i think it is sh~t that we have to deal with this; but some of us do. There is no doubt that there is/was something wrong in the layup process for some of our boats - but my belief is - there is nothing the factory will do to help. Anyway - my dealer addressed the issue last year - will pull the boat and evaluate the success of his work at the end of this week. I am not the most experienced boater - but blistering - that covers wide areas of the hull - need to be addressed in an immediate and urgent manner.

How big? diameter size ? I have lots that are smaller than a pin head I keep an eye on them every year. No getting bigger not getting more numerous that I can see.

[capt. black]

I got them too. I spent this weekend cleaning, tightening, and while srubing the bottom I
found several small pimple like blisters. The body guy at the marina says I have to repair this before I put the boat in the water. This will destroy the boat's value if the hull's fiberglass woven takes on water. I will either give them 1300.00 or buy a sander, and dit it myself.
I know WestMarine sells a epoxy primer, how far down do I sand before applying the primer.
When I finish sanding how do I remove excess dust from the sanding off of my boat?

[c130king]

There is a pretty good article on taking care of blisters in April 2009 Sail Magazine. I can't seem to open the article on the website. If I can get it to open I will link it.

Cheers,
Jim

[Dave Mason]

Thanks, guys, for your informative replies. The link to Nigel Klegg's article on Osmotic action was like finding the Bible on this problem. http://www.passionforpaint.co.uk/pdf/osmosis3v6.pdfshould get you there. He even says boats with color infused in the hulls are even more prone to blistering. It is caused by incomplete curing during layup, and could come from inside the ballast tanks just as easily. If you don't get it, count yourself lucky, you must have a Wednesday boat. Mine's a Monday or Friday . But the upshot is there isn't much can be done to remedy the situation at this point, just wait until repairs are absolutely necessary, like when the hull is weakened from delamination, and deal with it then. I'm putting in as soon as the weather is favourable. Fugeddaboudit. And think about how much cheaper the Mac is anyway.

[Obelix]

Just a thought.
Blisters supposedly come from water finding its way into the glass, which would explain the appearance of them where the ballast tank and channels are.
Has anybody thought if it would be possible to cut an access hole into the top of the ballast tank and put a barrier coat into the bottom of the tank and by pushing a brush through into the bottom of the channels?
Finally one could close the tank back up by glassing a new cover over the access hole.

[Mark J]

An Interlux pamphlet I picked-up mentions blister caused by reasons other than osmosis. Specifically, it refers to a "rash" of small pinhead blisters that are hard & dry. It says these are typically caused by air voids. This description matches some of the blister photos that have been posted on this site. They sound relatively benign.
And they're trying to sell Interprotect 2000.

Mark

[daydreamerbob]

How big? diameter size ? I have lots that are smaller than a pin head I keep an eye on them every year. No getting bigger not getting more numerous that I can see.

it was not the size that bothered me as much as the bottom of the hull looking and feeling like a football - from bow to stern and from port water line to stbd. boat rash!

[MSN-Travelers]

I got them too. I spent this weekend cleaning, tightening, and while srubing the bottom I
found several small pimple like blisters. The body guy at the marina says I have to repair this before I put the boat in the water. This will destroy the boat's value if the hull's fiberglass woven takes on water. I will either give them 1300.00 or buy a sander, and dit it myself.
I know WestMarine sells a epoxy primer, how far down do I sand before applying the primer.
When I finish sanding how do I remove excess dust from the sanding off of my boat?

Not sure if we have full blown blisters but we do have some sort of problem. Just about the entire bottom of my boat has raised bumps a little bigger than a pinhead. Here is a shot that shows the bottom.



I'm going the DIY route with a random orbital sander and 80 Grit. I am surprised how quickliy the bottom smoothed out with minimal pressure/sanding.

I plan on removing the dust with a simple water wash, towel dry followed by air drying. I will remove any wax that may haved survived the sander with Interlux's Fiberglass Prep Wash 202 and then put on four coats of Interprotect 2000E to the boot stripe. This will put a hard epoxy barrier between the gelcoat and the water. If the source of our problem is from the ballast tank ... I guess those of us that leave our boats in the water are screwed in the long run.

I will finish the bottom off with a couple coats ot Pettit Vivid, a hard finish, multi-season anti-fouling paint suitable for boats that may be hauled on a trailer periodically. I haven't figured out if I will take this to the boot stripe leave an inch or two of white showing.

[Rob S]

I'm going the DIY route with a random orbital sander and 80 Grit. I am surprised how quickliy the bottom smoothed out with minimal pressure/sanding.

I plan on removing the dust with a simple water wash, towel dry followed by air drying. I will remove any wax that may haved survived the sander with Interlux's Fiberglass Prep Wash 202 and then put on four coats of Interprotect 2000E to the boot stripe. This will put a hard epoxy barrier between the gelcoat and the water.

That's what I did two years ago (followed by bottom paint). It worked! No re-occurence.

[c130king]

All,

This issue has come up before and I think there was some consensus that thes "small bumps" can possibly be from the paint job (if you have one) rather than blisters.

I have a "football texture" on my boat. But after discussing this here in previous threads and then calling my PO I/we determined that the "bumps" are from the 4 x coats of "barrier paint" and not from blisters.

At least I hope so. The PO thinks I have no blisters...just a thick/bumpy paint job that he did himself.

If you have the bumps and have no paint job then all bets are off.

Good Luck,
Jim