Blisters? Bubbles in gelcoat when applied? Pox?

[WoodFamSkipper]

Hi All
I've had a good read through threads on blistering, huge quotes for repairs, getting by with barrier coats etc - and I wanted to fish for some opinions of my config and current challenge.

I've seen people ask Minaret for help - hoping they are still active on the CF

The boat has been on the hard for 1.5 to 2 years.
Short amount of time in water for sea-trial during survey, maybe an hour or so
Surveyors moisture readings were low and of no concern
Surveyor did sounding test and gave thumbs up, also did an Infrared scan and found no anomalies

I had another thread going about Wet Glass Blasting years of multi-layered paint jobs and the holes that have been left behind are what I'm asking about now.

Could it be bubbles in the gelcoat as it was applied back in 2005 at the Beneteau factory in France? (If near the Champagne region...perhaps bubbles are a cultural luxury?)

Could it be the not often seen embryos of osmotic blisters?

Some of them are more solitary and wider than the others that are found in long linear clusters, possibly hinting at "not bubbles"
I can see fiberglass threading in pretty much all of them

Big question: What would be best to fill them with?
I'm in Palm Beaches FL and have access to a West Marine nearby, but also Boat Owners Warehouse and other smaller indies.

As much as the blasting lost me a bunch of gelcoat that I was hoping to avoid - it did unearth these blips which I figure better to deal with now than ignore

The pictures include a flat AA battery for scale - the more commonly used quarter/dime/penny are completely absent from my possession due to my flatlined boat budget

[Bleemus]

That is the roughest glass blast I have ever seen. Holy crap. And yes those are what is left of blisters after that hack blasted the crap out of your hull. Your going to have to refair the whole bottom.

[WoodFamSkipper]

Originally Posted by Bleemus

That is the roughest glass blast I have ever seen. Holy crap. And yes those are what is left of blisters after that hack blasted the crap out of your hull. Your going to have to refair the whole bottom.

Is it the final texture that's rough?
Or the bad finish of blasted to buffed gelcoat?
I'm pretty disappointed in how the tape line has come out, still some scraping to do in some spots and a bunch of sand and polish to buff out over-blasted spills
Even got my bootstrap in a couple places

[minaret]

Originally Posted by WoodFamSkipper

Hi All
I've had a good read through threads on blistering, huge quotes for repairs, getting by with barrier coats etc - and I wanted to fish for some opinions of my config and current challenge.

I've seen people ask Minaret for help - hoping they are still active on the CF

The boat has been on the hard for 1.5 to 2 years.
Short amount of time in water for sea-trial during survey, maybe an hour or so
Surveyors moisture readings were low and of no concern
Surveyor did sounding test and gave thumbs up, also did an Infrared scan and found no anomalies

I had another thread going about Wet Glass Blasting years of multi-layered paint jobs and the holes that have been left behind are what I'm asking about now.

Could it be bubbles in the gelcoat as it was applied back in 2005 at the Beneteau factory in France? (If near the Champagne region...perhaps bubbles are a cultural luxury?)

Could it be the not often seen embryos of osmotic blisters?

Some of them are more solitary and wider than the others that are found in long linear clusters, possibly hinting at "not bubbles"
I can see fiberglass threading in pretty much all of them

Big question: What would be best to fill them with?
I'm in Palm Beaches FL and have access to a West Marine nearby, but also Boat Owners Warehouse and other smaller indies.

As much as the blasting lost me a bunch of gelcoat that I was hoping to avoid - it did unearth these blips which I figure better to deal with now than ignore

The pictures include a flat AA battery for scale - the more commonly used quarter/dime/penny are completely absent from my possession due to my flatlined boat budget

Sounds like you had a good thorough survey, this is most likely just a bit of gelcoat pox, which can be caused by many things but is most often just a poorly rolled out skin coat leading to small air bubbles in the glass in the first layers. Be sure to barrier coat thoroughly as this is a condition which can lead to more severe blistering if left unattended. I'd recommend you fill all blisters/voids with 3M Premium Filler and then sand the whole bottom. I'd use an 8" softpad sander but a DA is more forgiving for the average user. Sand off the remaining bottom paint remnant and sand out your pinhole fills at the same time. Use 40-60 grit. Then roll apply 5 coats of Interlux 2000, following instructions carefully and never mixing more than you can apply in a single day/coat. Be sure to catch the bond window after the final coat, this is the reason for an odd number of coats. You can generally (unless it's cold out) do two coats per day of barrier, then apply final coat of barrier in the morning of final day, first coat of AF in the afternoon. Don't miss this bond window; use the fingerprint test. Don't worry too much about gelcoat loss; the barrier replaces it. Only reason not to remove it is that the bare glass underneath will be full of pinholes that will need to be filled/faired. So don't burn through or you'll have to go back and fill a bit; other than that don't worry about it. Double or triple tape the waterline and then hand sand it with 60-80 grit. Make the blaster guy make any damage above the waterline right, that's not OK IMHO. He should have masked off heavily, it's a basic part of the job. I would never blast without covering the entire vessel above the waterline AND tenting the bottom to contain dust/abrasives. But I only blast alloy vessels. It's lots of work, dive in and good luck!

[Cheechako]

Those don't look too bad at all. Yes just fill them with minaret's recommendation, or any kind of epoxy as far as that goes. Put a good barrier coat on. I cant blow up the pics for some reason but that surface doesn't look too bad to me.

[WoodFamSkipper]

Originally Posted by minaret

Sounds like you had a good thorough survey, this is most likely just a bit of gelcoat pox, which can be caused by many things but is most often just a poorly rolled out skin coat leading to small air bubbles in the glass in the first layers. Be sure to barrier coat thoroughly as this is a condition which can lead to more severe blistering if left unattended. I'd recommend you fill all blisters/voids with 3M Premium Filler and then sand the whole bottom. I'd use an 8" softpad sander but a DA is more forgiving for the average user. Sand off the remaining bottom paint remnant and sand out your pinhole fills at the same time. Use 40-60 grit. Then roll apply 5 coats of Interlux 2000, following instructions carefully and never mixing more than you can apply in a single day/coat. Be sure to catch the bond window after the final coat, this is the reason for an odd number of coats. You can generally (unless it's cold out) do two coats per day of barrier, then apply final coat of barrier in the morning of final day, first coat of AF in the afternoon. Don't miss this bond window; use the fingerprint test. Don't worry too much about gelcoat loss; the barrier replaces it. Only reason not to remove it is that the bare glass underneath will be full of pinholes that will need to be filled/faired. So don't burn through or you'll have to go back and fill a bit; other than that don't worry about it. Double or triple tape the waterline and then hand sand it with 60-80 grit. Make the blaster guy make any damage above the waterline right, that's not OK IMHO. He should have masked off heavily, it's a basic part of the job. I would never blast without covering the entire vessel above the waterline AND tenting the bottom to contain dust/abrasives. But I only blast alloy vessels. It's lots of work, dive in and good luck!

I am on it! Think I got the less premium filler (ooops) but am trying to rectify the holes
Will be doing the 5 coats of base to get it nice and sturdy under the water line
Thanks for the feedback, keep your fingers crossed for me
All the best!

[minaret]

Originally Posted by WoodFamSkipper

I am on it! Think I got the less premium filler (ooops) but am trying to rectify the holes
Will be doing the 5 coats of base to get it nice and sturdy under the water line
Thanks for the feedback, keep your fingers crossed for me
All the best!

Attachment 144251

Yeah that's the same filler but with added fibers for reinforcement, also marketed as Blister Repair. It's fine to use but is overkill for small blisters/pinholes like this, it's a real bear to sand out, like sanding cement. Just makes it harder with no real benefit,IMHO.

[Suijin]

Originally Posted by Bleemus

That is the roughest glass blast I have ever seen. Holy crap. And yes those are what is left of blisters after that hack blasted the crap out of your hull. Your going to have to refair the whole bottom.

I think the strongly raked light in the pictures makes it look rougher than it actually is. That looks pretty much like every media blasting job I've ever seen, give or take.

[WoodFamSkipper]

Originally Posted by minaret

Yeah that's the same filler but with added fibers for reinforcement, also marketed as Blister Repair. It's fine to use but is overkill for small blisters/pinholes like this, it's a real bear to sand out, like sanding cement. Just makes it harder with no real benefit,IMHO.

Totally get what you mean - luckily I only bought a pint to get me started. Another guy at the yard stopped by and said it was gonna be resistant to sanding too

A pint has got me just over a quarter of the boat done. Mainly due to me mixing too much and it setting too quick on me (learning the wasteful way)

Think I'll get a quart of the other type for the remaining 3/4 of the boat

[rbk]

I would be very cautious wet bonding your AF to your barrier coat. Some have been known to cause extreme chemical blistering and complete failure of both the barrier and AF bond and cure causing more extensive repairs than the initial repair was designed to do.

[WoodFamSkipper]

Originally Posted by rbk

I would be very cautious wet bonding your AF to your barrier coat. Some have been known to cause extreme chemical blistering and complete failure of both the barrier and AF bond and cure causing more extensive repairs than the initial repair was designed to do.

If they were both of the same brand/manufacture - would that compatibility be a safe bet for chemical bond?
I'm looking at Interlux 2000e and the MicronCS to go atop of it

[rbk]

Just follow the instructions and check compatibility. If the manufacturer says to then do it. If not I wouldn't risk it.

[bsurvey]

gel coat was applied too thin to begin with

[Cadence]

"Be sure to catch the bond window after the final coat, this is the reason for an odd number of coats." Probably the important item that will most likely be ignored from minarets post. Bond window being important term. It isn't oh hell one more day won't hurt,

[WoodFamSkipper]

Originally Posted by Cadence

"Be sure to catch the bond window after the final coat, this is the reason for an odd number of coats." Probably the important item that will most likely be ignored from minarets post. Bond window being important term. It isn't oh hell one more day won't hurt,

I 100% have that part set in mind
The previous layers were flaking apart - I do t want my new coverage to do the same

On this topic point...how do you wake up the first two coats the next morning? Sanding?

Another question....the Interlux brochure talks about SolventWash202 to remove surface debris
Is there a no brand name for that chemical ? And what is best to use to wipe down? Sponges/cloths?