Should I keep sanding?

[leftbrainstuff]

Way too much buildup there

[Quadrille in JB]

Why hasn’t anyone stressed the need for a 2-part barrier coat over the clean gel coat to seal the hull and prevent future blisters? This goes on before the anti-fouling bottom paint
This is very important in my opinion...

[Clamdigger]

Because some of those are epoxy based which doesnt completely, or perfectly, bond with polyester resin of which the majority of boats were constructed. So its expensive way to 'seal' a polyester hull.

[ferrailleur]

Originally Posted by SV_Harbinger

That is a lot of paint build up, I would forgo the sander in favor of a grinder and a paint/rust stripping wheel, just be careful not to dig into the hull as they will chew fiberglass/grp and be fairly happy to do so. Alternately a soda blast or similar probably wouldn't be a bad idea either. Just my 2¢

Thanks, I'll probably call Mikes Soda Blasting (Annapolis area) who is hight recommended.

[ferrailleur]

Originally Posted by Clamdigger

Because some of those are epoxy based which doesnt completely, or perfectly, bond with polyester resin of which the majority of boats were constructed. So its expensive way to 'seal' a polyester hull.

Thanks, if I have the hull stripped off all paint via soda blasting, what barrier coat do you recommend? I was thinking of Interlux (Interprotect 2000) which an epoxy protection (2-3 coats)

[ferrailleur]

Originally Posted by gamayun

In that second picture of yours, you can see where someone painted over a flaked out section. That is how my boat looked. It was not possible to just sand it back lightly to get to "good paint" because there wasn't any, and the new paint won't bond to that. It's a helluva job to sand it all off, but you'll also want a clean surface to put an epoxy layer down after the blister repair and get the whole bottom fixed for good. Sail Life on YouTube did an amazing job documenting this work but he tends toward uber-perfection.

You're right. Better doing it right the first time. I'm going to have the hull soda blaster, then:
- repair blisters
- 2 coats of epoxy barrier
- 2 coats of antifouling


What do you think?

[ferrailleur]

Originally Posted by Quadrille in JB

Why hasn’t anyone stressed the need for a 2-part barrier coat over the clean gel coat to seal the hull and prevent future blisters? This goes on before the anti-fouling bottom paint
This is very important in my opinion...

That's exactly what I have in mind:
- soda blasting
- repair blisters
- 2 coats of epoxy barrier coat
- 2 coat of antifouling
What do you think?

[ferrailleur]

Originally Posted by Clamdigger

Because some of those are epoxy based which doesnt completely, or perfectly, bond with polyester resin of which the majority of boats were constructed. So its expensive way to 'seal' a polyester hull.

What would you recommend?
What do you think of what I plan which is in reply to above or below postings?
Thank

[Pete7]

Originally Posted by ferrailleur

Thanks, if I have the hull stripped off all paint via soda blasting, what barrier coat do you recommend? I was thinking of Interlux (Interprotect 2000) which an epoxy protection (2-3 coats)

I thought it was more like 5 coats. Vary the colour so you can easily see the bits you have painted properly coat by coat.

Pete

[ebsail]

Our 35 year old Oday 25 looked even worse when we got it. We thought the first coat of paint may not of bonded well. We chipped off the many coats of paint with 2" wide scrapers. Lots of big chunks came right off so it only took 2 days for two of us to completely strip the hull to almost clean bare hull. Using a narrow scraper allowed us to use more force over a smaller area and made the job easier. Just a tarp under the boat gathered the paint chunks. Using work gloves cushions your hands. A light sanding finished the job. Its worth a try. Two good scapers cost $20 total

[ferrailleur]

Originally Posted by ebsail

Our 35 year old Oday 25 looked even worse when we got it. We thought the first coat of paint may not of bonded well. We chipped off the many coats of paint with 2" wide scrapers. Lots of big chunks came right off so it only took 2 days for two of us to completely strip the hull to almost clean bare hull. Using a narrow scraper allowed us to use more force over a smaller area and made the job easier. Just a tarp under the boat gathered the paint chunks. Using work gloves cushions your hands. A light sanding finished the job. Its worth a try. Two good scapers cost $20 total

I'm too lazy to do what you have done!
Congrats on your refinishing.
I have hired a recommended business to soda blast the hull. I will be there every step of the way to make sure it's done to my liking.
I will post a pic next week.
Thanks for your answer

[gulfislandfred]

If you use an air powered sander, you can sand wet, which keeps the dust down. You don't need a lot of water. You can use open grit discs, and rinse them a few times, so they last longer.


Good idea to do it all, dig out the blisters, and put on a barrier coat. I think epoxy/tar is the best barrier coat. Here in BC, Canada, I can get it from an industrial paint supplier for a much lower price than the "marine" brand.

[guyrj33]

Originally Posted by coastalexplorer

I would recommend blasting it with water and glass frit to take it right back to where all the damage is visible. cover and dry it out, Then do all the glass repairs. Epoxy resin is pollution on a polyester resin built hull. Save you money and spare yourself future aggravation...use The same material that the hull is made from for all repairs and finishing. BTW there are some materials that Epoxy will NOT stick too.
It is not the go-too miracle cure for all ills.

WOW totally FALSE!
Properly applied epoxy will form stronger bonds on polyester than polyester will.

[carlheintz]

Just a reminder: be sure to wear breathing protection, eye protection, and skin protection. Yea, this is really bad stuff you're dealing with, and getting it on your skin, in your lungs or in your eyes is really dangerous. BTW those little filter masks they sell for 50cents are not going to do you much good.

[guyrj33]

Originally Posted by carlheintz

Just a reminder: be sure to wear breathing protection, eye protection, and skin protection. Yea, this is really bad stuff you're dealing with, and getting it on your skin, in your lungs or in your eyes is really dangerous. BTW those little filter masks they sell for 50cents are not going to do you much good.

Really bad stuff? Which stuff are you referring to as hazardous, the Dihydrogen Monoxide (DHMO) used to clean the hull, it is perhaps the single most prevalent of all chemicals that can be dangerous to human life.