osmosis blister advice - puzzled ??

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BOATKID

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getting conflicting advice on how to deal with 3 or 4 blisters

plastic padding website says
Plastic Padding Marine Epoxy is a fast setting epoxy filler for repairing osmosis damage, filling holes and scratches above or below the waterline. It seals and joins GRP, wood, steel, alloy, iron and ferro-cement. Gives a hard resilient water resistant repair which withstands petrol, diesel etc.

It can be applied in thick layers without the risk of shrinkage or cracking. can be painted with all or one or two component marine paints. An epoxy primer is recommended before applying top coat



but local fibre glass stockist says Epoxy with Colloidal Silica then sealed with gelcoat
 
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BOATKID said:
getting conflicting advice on how to deal with 3 or 4 blisters

plastic padding website says
Plastic Padding Marine Epoxy is a fast setting epoxy filler for repairing osmosis damage, filling holes and scratches above or below the waterline. It seals and joins GRP, wood, steel, alloy, iron and ferro-cement. Gives a hard resilient water resistant repair which withstands petrol, diesel etc.

It can be applied in thick layers without the risk of shrinkage or cracking. can be painted with all or one or two component marine paints. An epoxy primer is recommended before applying top coat



but local fibre glass stockist says Epoxy with Colloidal Silica then sealed with gelcoat
Click to expand...
The former might work - the latter is what the professional would do.
 
Before you panic, are you sure you have Osmosis ?

Often, if the antifouling is more than one coat, bubbles appear, but they are not due to Osmosis, but instead to moisture trapped between coats. Then after a time, they mysteriously disappear.
 
How far do yo want to go....

VO5 said:
Before you panic, are you sure you have Osmosis ?

Often, if the anti-fouling is more than one coat, bubbles appear, but they are not due to Osmosis, but instead to moisture trapped between coats. Then after a time, they mysteriously disappear.
Click to expand...

Even if it is osmosis still don't panic, the osmosis thing is hyped up to almost hysterical proportions.

It's your boat, you've said there are some blisters. How far do you want to go??? How concerned are you, how much money do you want to spend, how handy are you at doing things yourself.

If you just want to fill the blisters do this. Grind them out, a Dremel is a good tool for odd blisters but not essential, a large countersink in a drill bit if the blisters are no more than a centimeter ....small grinderette if larger, BE CAREFULL>>>>:eek:

If when opened the blisters bleed a foul smelling liquid treat them a little more seriously. Grind/clean them out with acetone and small brush (I use old tooth brushes) wash out with fresh water and allow to dry. If you've power handy a heat gun or hair dryer is handy. Get yourself some epoxy filler, not polyester. If you can't get a proprietary marine brand like Blake's use your Plastic Padding stuff. Allow to dry to hard and sand smooth to profile of hull.

Now...you can either just slap some primer and anti-foul on it or.......spend some money on two pack epoxy for underwater profiles. If you are going to spend on Epoxy the job is growing. Again how far do you want to go, get the hull tested for moisture content...blah...blah... blah.... I could write all night on this stuff because it's incorporated into what I do for a living but heh! it's over to you to get back, I could be wasting my time....:D
 
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Osmosis? Don't worry about it. It'll send you to the grave. Good God man, you can hardly see the feckers!

Gouge out the bubbles and fill them in. Slap some cold tar epoxy over the top.

My mate has owned a 45 year old Westerly for about twenty years. It's had some blisters between the keels for all the time he has owned it. So what? The thing keeps sailing and get's him home safe every time!

There are children being macheted in Africa, there are entire solar systems being sucked in by black holes somewhere....and there's you worrying about a couple of blisters on the bottom of your boat.

Enjoy your boat...go sail the thing. :D
 
Well said that man.......

skodster said:
Osmosis? Don't worry about it. It'll send you to the grave. Good God man, you can hardly see the feckers!

Gouge out the bubbles and fill them in. Slap some cold tar epoxy over the top.

My mate has owned a 45 year old Westerly for about twenty years. It's had some blisters between the keels for all the time he has owned it. So what? The thing keeps sailing and get's him home safe every time!

There are children being macheted in Africa, there are entire solar systems being sucked in by black holes somewhere....and there's you worrying about a couple of blisters on the bottom of your boat.

Enjoy your boat...go sail the thing. :D
Click to expand...

Well said that man.....
 
saxonpirate said:
Even if it is osmosis still don't panic, the osmosis thing is hyped up to almost hysterical proportions.

It's your boat, you've said there are some blisters. How far do you want to go??? How concerned are you, how much money do you want to spend, how handy are you at doing things yourself.

If you just want to fill the blisters do this. Grind them out, a Dremel is a good tool for odd blisters but not essential, a large countersink in a drill bit if the blisters are no more than a centimeter ....small grinderette if larger, BE CAREFULL>>>>:eek:

If when opened the blisters bleed a foul smelling liquid treat them a little more seriously. Grind/clean them out with acetone and small brush (I use old tooth brushes) wash out with fresh water and allow to dry. If you've power handy a heat gun or hair dryer is handy. Get yourself some epoxy filler, not polyester. If you can't get a proprietary marine brand like Blake's use your Plastic Padding stuff. Allow to dry to hard and sand smooth to profile of hull.

Now...you can either just slap some primer and anti-foul on it or.......spend some money on two pack epoxy for underwater profiles. If you are going to spend on Epoxy the job is growing. Again how far do you want to go, get the hull tested for moisture content...blah...blah... blah.... I could write all night on this stuff because it's incorporated into what I do for a living but heh! it's over to you to get back, I could be wasting my time....:D
Click to expand...

I agree with you the whole osmosis thing is overdone. But owners who have it on their boats don't like it and it worries them. If it is any consolation, no boat has ever sunk or even increased its draft because of it, or even leaked because of it.
 
thanks guys for all your inputs, I am not undully worried about the blighters I just want to keep them at bay and am just trying to get my remedial strategy right
 
Boo2 said:
Would the gelcoat in that case be epoxy gelcoat or polyester ?

Boo2
Click to expand...

As the work is below the waterline and will be covered by anti foul the normal practice is to coat the repair with 4 coats of epoxy to prevent further moisture entry; this is normally coated with an epoxy primer prior to anti fouling.

Poly resins don't stick too well to epoxy, but epoxy sticks well to poly resins and is more resistant to moisture.

Good luck. :)
 
as an aside I read on a website today that i could use a steamer to decontaminate and then a paint stripper/hairdryer to speed the drying process up !!

anyone agree ??
 
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