Dealing with Shallow Blisters ... Pics Enclosed

[Bash]

Originally Posted by delmarrey

Peelers can be rented in most port cities. But what ever you decide, I'd recommend a full epoxy barrier coat over the bottom to prevent any more saturation.

+1 on a barrier coat. No matter whether you decide to peel or not.

[sharpey]

Thanks for that...

Will have a look into renting one... fingers crossed...

And definitely going to barrier coat!

Cheers

James

[Cheechako]

If the bottom, as it sits, has time to dry out, I think a couple coats of epoxy resin will seal it up fine. You have now exposed the glass so it should be dryng out as we speak. A lot of boats have been done without peeling. From the discussion, it doesnt sound like your saturation is real deep....

[sharpey]

Thanks for your reply.

I'm kind of leaning in this direction... just due to the fact that getting a peeler is going to cost a lot, and then doing lots of reglassing (something I'd need to become expert at) would add greatly to the complexity...

I know that this is the proper way to do it. I think we're going to see how far we can get by doing what you've just suggested... i.e. grind/sand all these blisters out... get the hull as fair as possible before doing any actual fairing... then put a diluted sealing epoxy on to seal up the voids in the mat, and the resin that wasn't ground for blisters (you can see these pin holes)... and then fair, barrier coat, and paint... Sounds like enough work already!


But really, all your replies are much valued... thanks for taking the time!

Cheers,

James

[Bash]

We want pictures of the finished project!

[minaret]

Originally Posted by sharpey

Thanks for your reply.

I'm kind of leaning in this direction... just due to the fact that getting a peeler is going to cost a lot, and then doing lots of reglassing (something I'd need to become expert at) would add greatly to the complexity...

I know that this is the proper way to do it. I think we're going to see how far we can get by doing what you've just suggested... i.e. grind/sand all these blisters out... get the hull as fair as possible before doing any actual fairing... then put a diluted sealing epoxy on to seal up the voids in the mat, and the resin that wasn't ground for blisters (you can see these pin holes)... and then fair, barrier coat, and paint... Sounds like enough work already!


But really, all your replies are much valued... thanks for taking the time!

Cheers,

James

Whatever else you do, just make sure to get a moisture meter on it and don't apply anything until its dry. Otherwise you'll be going through all this again in a few years.

[justwaiting]

Originally Posted by minaret

Whatever else you do, just make sure to get a moisture meter on it and don't apply anything until its dry. Otherwise you'll be going through all this again in a few years.

The OP apears to have made his mind up so while we have your attention a minor hijack.

When removing the gel coat should you stop at the water line or continue upwards if the meter indicates saturation of the sub-strata above the waterline?

The barrier coat (2000) is there any value in extending it above the waterline?

Thanks in advance

[sharpey]

Hijack away

For what it's worth, I've read that 2 inches above the waterline is a good idea... and so I've just gone to the top of the boot strip... where it would seem the gelcoat is extra thick... as if almost to spite me...


But yes, I have made my mind up... thanks for helping me get there!

Will be taking pictures and keeping you all updated... (no really... I promise)...

Am going to tent and dehumidify... and not do anything until it's dry... my surveyor has said he'll pop by with his moisture meter now and again to see how things are progressing... nice chap.

Cheers,

James

[minaret]

Originally Posted by justwaiting

The OP apears to have made his mind up so while we have your attention a minor hijack.

When removing the gel coat should you stop at the water line or continue upwards if the meter indicates saturation of the sub-strata above the waterline?

The barrier coat (2000) is there any value in extending it above the waterline?

Thanks in advance

It's fairly common for high moisture readings and even blisters to continue for as much as a foot or so above the waterline. In this case you should also peel as high as the high readings go, to assist drying. As long as the waterline is properly placed, ie a couple of inches higher than it needs to be, then carrying the 2000 above the waterline has no benefit, and may even have drawbacks if you are going to topcoat over it when painting the hull. Often we find that a blister job is a great time to raise the waterline an inch or two, allowing us to do the job without painting the hull, just restriping. Obviously you can't do this if the saturation goes a foot above the waterline, at that point you are in for a hull paint job as well. Also a great time to add an accent stripe, I can't fathom why most manufacterers don't do this, most boats look much better that way IMHO.

[delmarrey]

Originally Posted by minaret

It's fairly common for high moisture readings and even blisters to continue for as much as a foot or so above the waterline. In this case you should also peel as high as the high readings go, to assist drying. As long as the waterline is properly placed, ie a couple of inches higher than it needs to be, then carrying the 2000 above the waterline has no benefit, and may even have drawbacks if you are going to topcoat over it when painting the hull. Often we find that a blister job is a great time to raise the waterline an inch or two, allowing us to do the job without painting the hull, just restriping. Obviously you can't do this if the saturation goes a foot above the waterline, at that point you are in for a hull paint job as well. Also a great time to add an accent stripe, I can't fathom why most manufacterers don't do this, most boats look much better that way IMHO.

If in Singapore as your personal details suggest, you may want to tent it up, from the waterline down, for a couple days before applying filler/barrier coat and use dehumidifiers to finish the drying. The weather averages around 80-85% all year long. The hull will only dry out as much as the ambient air around it w/o help.

[sharpey]

quite right... Am researching where to get appropriate equipment to do just that...

Cheers

[justwaiting]

@minaret

With the permission of the OP and your invertation to ask away

On the subject of peelers: from the demo vidio on another thread it apears that the gauge that sits on the uncut section of the surface to be cut would be effected by uneven surfaces?

If this is correct how much effort is worth putting into removal of growth residue on the hull?

Would the grinding out of visable blisters before using the peeler effect the fairness of the surface left by the peeler?

Would the mulicut required in some cases reduce this problem?

If that is the case at what point of time is it desireable to make the decission to use the peeler?

Better still just give us the answers to the questions i should have asked

[minaret]

Originally Posted by justwaiting

@minaret

With the permission of the OP and your invertation to ask away

On the subject of peelers: from the demo vidio on another thread it apears that the gauge that sits on the uncut section of the surface to be cut would be effected by uneven surfaces?

The offset shoulder rides on the uncut section, which means the cutter head is perfectly reproducing any divots/unfairness in the hull.


If this is correct how much effort is worth putting into removal of growth residue on the hull?

We always do a bottom paint removal first before peeling. The peeler doesn't like bottom paint, it's bad for the machine. Also this gives you a fair surface to peel on, if you didn't do this the blisters themselves would be a problem. The bottom paint removal is done with 36 grit softpads, which takes it down to the original gelcoat and knocks the tops off the blisters. This also means the whole job is much cleaner and safer for the peeler operator because he does not need to wear a fullface with heavy suiting. The peeler is such a dangerous machine that you really want tight clothing with minimal gear instead of the full suit-up.

Would the grinding out of visable blisters before using the peeler effect the fairness of the surface left by the peeler?

Dramatically. You want to peel from the original gel because you know that surface is fair. Any divots you may pre grind in the hull will be perfectly reproduced by the peeler but made slightly larger.

Would the mulicut required in some cases reduce this problem?

No, each pass would make the divot slightly larger. A bad idea for a fair hull.

If that is the case at what point of time is it desireable to make the decission to use the peeler?

Before touching the bottom with anything other than a pressure washer is the time to make a decision on peeling or not.

Better still just give us the answers to the questions i should have asked

Hope that helps!

[Cheechako]

Originally Posted by sharpey

Thanks for your reply.

I'm kind of leaning in this direction... just due to the fact that getting a peeler is going to cost a lot, and then doing lots of reglassing (something I'd need to become expert at) would add greatly to the complexity...

I know that this is the proper way to do it. I think we're going to see how far we can get by doing what you've just suggested... i.e. grind/sand all these blisters out... get the hull as fair as possible before doing any actual fairing... then put a diluted sealing epoxy on to seal up the voids in the mat, and the resin that wasn't ground for blisters (you can see these pin holes)... and then fair, barrier coat, and paint... Sounds like enough work already!


But really, all your replies are much valued... thanks for taking the time!

Cheers,

James

I agree, no point in making this a whole boat repaint! BTW, there is an article in this months Cruising World about the same thing. His bottom looks similar to yours. He did as you are planning I believe... saturating the "dry" layers well now that the bottom is cleaned off.

[justwaiting]

Originally Posted by minaret

Hope that helps!

Yes, helps a lot. Thanks for your time and knowledge. At the very least it helps us ask the right questions if we are trying to evaluate what we are being told by "professionals" even if we are not going down the DIY path.
Regards & Thanks