Bottom Blasting

[casual]

I,just purchased this boat and have no idea whats under the botttom paint.Surveying the boat in Dec 2011 showed a Solid hull that included Ultra sound checking.The boat had been on the Hard for 8 Months at that time.NO blisters were present.The boat was lanunched in Dec 2011 for sea trial and remained in the water.After completing a trip Home to Fl in May 2012 I,hauled and found no blisters.I,figure after 6 months if some were there they would show.Now I,am thiinking of bead blasting the bottom to remove old paint buid up and applying a barrier coat,does not have one now.I,am concerned if after 30 years and no blisters present and as a foot note Moister meter reading low,am I,opening a can of worms,should I,just leave well enough alone.The Co that does the blastngis ECO STRIP LLC suppose to be Good and assured non damaging.Sory to be so long winded,Please opinions and past experience.
Thanks All

[FSMike]

Sounds like a lot of trouble and expense to fix something that isn't broken. I might have something like a soda blasting job or other non damaging procedure done to remove the old paint but I wouldn't spend the bucks on a barrier coat.

[Cheechako]

It would never hurt to barrier coat it , for sure. Sounds like you dont have a an issue though. Did the PO haul out every winter? If he did and you dont and are in warmer waters , the pox could start...

[Ziggy]

I guess if no blisters developed in the past 30 years, they are not likely to develop now. Unless the boat was previously in the water only seasonally and now you're keeping it in the water year round.

Another consideration is how many layers of bottom paint you have on, and how well it adheres. If the bottom paint is peeling, you might want to remove it just to get a nice smooth bottom. But generally, I agree with FSMike--if it ain't broke, don't fix it. I have relearned that lesson more times than I care to remember.

[David M]

If you ever do get down to bare fiberglass, I would definitely apply a moisture barrier coat. It's good insurance. Otherwise, leave well enough alone.

[Fiberglass1Inc]

Eco Strip is VERY good at cleaning off bottom paint. Some of the jobs I've seen them do in the yard I work out of have been phenomenal.
But if you strip it, do not consider the barrier coat optional in any way. Once the gel coat is "opened up" it has to be epoxy coated. After stripping, wash it every other day with copious amonts of fresh water. Odd as it sounds this facilitates drying. And don't scrimp on the barrier coat - 4 coats minimum, 5 better.

[casual]

Ok my bottom paint is KaPut Flaking and peeling.I,need to either remove the bottom paint down to Gelcoat and barrier coat or just rought sand the bottom and paint.I,aggeree that after removing the bottom paint it would be foolish to not apply a barrier coat over the Gel Coat is my thinking Right?If I,do the paint removal it will be with ECO STRIP,my main concern is damage with Eco Strip causing damage to the Gel,I,am being stupid went thru this years ago Pealed the bottom coated ect lots of time and money and blisters developed after the process that wern't there before.mAYBE LUCK OF THE DRAW.
Thanks for all the input

[casual]

Fiberglass1Inc,any clue as to which barrier coat is best these day's the more I,read the more confussed i,become,used west system in the past.
Thanks

[Cheechako]

Some people call Interlux 2000 etc a barrier coat. It is nothing like the real thing :, Epoxy resin. 2 coats of real resin works for most people. I've often wondered if paint stripper doesnt soak into the very pourous gel coat....?

[casual]

Cheechako,I,ask that same question from Franmar SoY Bean Paint Stripper,They replided no,but not to use it on Epoxy will ahrm it.Go FigureHow about Vinallester resin,Seems boat buiders are using it now in the final lay up with good results.
Thanks for the input

[Ziggy]

Originally Posted by casual

Fiberglass1Inc,any clue as to which barrier coat is best these day's the more I,read the more confussed i,become,used west system in the past.
Thanks

I think Interprotect 2000 is very good.

[Fiberglass1Inc]

We've used Interprotect since it was introduced in 1980. Never had a problem. Used others during that time, had problems. There are no other products that we have used for over 30 years that have been this consistent. And Interprotect is "nothiong like the real thing"? Yeah, right!
We did 2 boats with the W.E.S.T. system many years ago, resin with their aluminum oxide powder added. The one that was done in the winter is fine all these years later. The one that was done in the Florida summer heat had 10 or 15 very minor blisters form 5 years after the job was done. The reason was outgassing between coats. It was a minor problem and we fixed them under warranty but the point is - Interprotect doesn't do that. I'm a huge fan of W.E.S.T. and we use it all the time, but not for blisters.
We have some boats that we did in the 80's that are still around and still blister free. In my view, you can't beat a product performance like that.
The biggest problem with blister jobs is incompetence. Looked at one yesterday where the divots had been filled with improperly catalyzed AwlFair! Were they serious? AwlFair? Jeez people, read the damn cans!!!!

[Fiberglass1Inc]

Vinylester only approaches the osmotic resistance of epoxy when ETC'd (elevated temperature cure). Without the precise elevation of temperature during cure the osmotic resistance is only slightly better than polyester. Isn't it amazing how few repair personell and sales reps know that?

[Ziggy]

One more thing-if you do use Interprotect, read the directions carefully and follow them to the letter. In particular, you need to apply the first coat of antifouling before the last coat of Interprotect is fully cured. Otherwise the bottom paint will not adhere well to the barrier coat.

[SVTatia]

Originally Posted by Fiberglass1Inc

Looked at one yesterday where the divots had been filled with improperly catalyzed AwlFair! Were they serious? AwlFair? Jeez people, read the damn cans!!!!

AwlFair label indicates its use for above or below the waterline.
What would be your recommendation for fairing compound?