All New Bottom: Redoing my T-26 Monohull in the Driveway

[withintheruins14]

I am stripping my sailboat's bottom back down to the gelcoat. I'm new to sailing and have a few questions I've been meaning to ask.

First off, I've felt a bit overwhelmed the past few days. While at first, we were able to get a lot of paint off fast - getting that last 5% has been exhausting. I've noticed more dinks in the boat stem, some large areas of delamination on the rudder, and I'm not sure what direction to go with these keels. My goal is to get the boat ready for the water asap. I want to sail this year yet. I've really been looking forward to the chance of asking other sailors plainly - What should I do next? What steps would be your top 5 to get this boat ready? Barrier coat is normally the next step, but I haven't been able to find a definitive answer online to the question: Is this sanded enough yet? Is 95% of the paint removed good enough before barrier coat? Can barrier coat go over small areas of delamination without first gel coated? What would be the easiest way to get the remaining 5% of paint off? Thanks!

Before Sanding:

After Sanding:

After First Pass Sanding Port Side:

Progress On Starboard Side:

After Sanding 95%+ of the Bottom and Barrier Paint:

Good Shot of the Keels:

 

[sail sfbay]

Welcome to the forum!! Lots of great questions and applaud you on doing this project yourself and great progress so far!! My wife and I sanded and painted to our first sailboat bottom and that was enough to give us some experience.

To remove the last 5% of paint consider stripping with a paint stripper/scraper or blasting with sand, bicarbonate of soda (baking soda, which is much less aggressive than sand and easier on the underlying gel coat) or dry ice (the impact of the very cold dry ice pellets provides a thermal shock to the painted surface that aids in breaking up and removing the old finish AND blasting medium sublimes into carbon dioxide gas, leaving only the paint residue to clean up) by a qualified contractor.

The yard did the following procedure a year and one-half ago after purchase of my Hunter 46 as a result of barrier coat failure, particularly on the keel due to lack of maintenance by the previous owner. Grind out all the corrosion products from the keel, fill in any cracks and voids with epoxy. Check the hull for dryness with a marine moisture meter to be sure it is ready for barrier coating. Then apply 5 - 7 coats of barrier paint followed by 2 coats of antifouling paint. Might refer to the following link entitled "How to barrier coat and bottom painting boat" and "A Smorgasbord of Tools and Patience are Required for the DIY Epoxy Barrier Coat Removal".

A Smorgasbord of Tools and Patience Are Required For the DIY Epoxy Barrier Coat Removal - Practical Sailor

Since 1974, Practical Sailor’s independent testing has taken the guesswork out of boat and gear buying.

www.practical-sailor.com

 

[LeeandRick]

Rudder: You may be able to inject some epoxy through small holes in the rudder and clamp the area. It might stick it might not. I did this and it worked for awhile or until our first 115 degree day on the trailer when the skin expanded. I'm going to rebuild the rudder this fall. A delaminated rudder is a failure waiting to happen since the load paths cannot be maintained.

Bottom: When we did our bottom on our 26' boat, 2 years ago, we sanded until it was all gelcoat. One way to tell if the barrier coat will stick is to take a clean rag with a serious solvent on it and very slowly wipe an area. If anything is on the rag keep sanding. I wore out a palm sander and the new one is on it's last leg. If you have any blisters or any scratches, repair them now before barrier coat. We had over a hundred dime sized blisters.

Keep sanding and good luck. Another Pulp Fiction fan.

 

[rgranger]

Go to Lowes and buy a 5 lb bag of garden lime and put it in a 5 gallon PVC bucket. Add two full cans of drain-O to that and then just enough water to get it to a melted peanut butter consistency while stirring. Spread that slop on the stubborn parts with a paint roller on a pole. Let it dry, pressure wash it off and most of the paint will come off with it. For the one or two stubborn spots, I use citrus strip and a scrapper.

DO NOT LET THIS STUFF GET IN YOUR EYES. Wear goggles and gloves.

 

[withintheruins14]

First off, huge thanks to all three of you for you help. I hope you took my silence this far as an indication that we've been out in the driveway working. Your posts were the push I needed to power through - having said that. Here is what the past few days have been like:

Last Sunday:
1. Applied think layer of Klean Strip Paint and Varnish Remover with very poor to poor results

Monday (Yesterday):
1. Applied 10/1 water/muriatic acid solution with spray on bottle with poor results. Yes, some paint came off, but it seems to have only made the existing white areas of gelcoat whiter - problem areas didn’t improve much.

Was the 10/1 ratio to weak? My plan going forward from here is to try a stronger ratio. Thanks again guys, I’m lucky to have you all! Phil

@sail sfbay @LeeandRick @rgranger

 

[rgranger]

So the approach I suggested is a base not an acid. Depending on the type of paint one is better than the other for removing. The strong caustic base will actually break some of the bonds in the paint and help it flake off. The recipe I suggested is essentially the same ingredients in the very expensive stuff called Peel Away. But you can make it for about $10 worth of supplies.

Good luck.
BTW: Muriatic Acid is another name for hydrochloric acid a.k.a. stomach acid (HCl).

 

[rgranger]

Another tid-bit. The active ingredient in Drain-O is potassium hydroxide (KOH). You can get it cheaper than Drain-O online through Walmart...

Potassium Hydroxide (KOH),90% pure, Caustic Potash, Organic Soap making 6 Lbs (Pounds) - Walmart.com

Buy Potassium Hydroxide (KOH),90% pure, Caustic Potash, Organic Soap making 6 Lbs (Pounds) at Walmart.com

www.walmart.com

OR if you have another source for KOH that will also work. What you really need is the -OH part of that salt... so sodium hydroxide (NaOH) will work even better because sodium salts are more water soluble than potassium salts.... but for some reason NaOH is harder to find ...unless you work in a lab.

 

[jviss]

Another tid-bit. The active ingredient in Drain-O is potassium hydroxide (KOH). You can get it cheaper than Drain-O online through Walmart...

Potassium Hydroxide (KOH),90% pure, Caustic Potash, Organic Soap making 6 Lbs (Pounds) - Walmart.com

Buy Potassium Hydroxide (KOH),90% pure, Caustic Potash, Organic Soap making 6 Lbs (Pounds) at Walmart.com

www.walmart.com

OR if you have another source for KOH that will also work. What you really need is the -OH part of that salt... so sodium hydroxide (NaOH) will work even better because sodium salts are more water soluble than potassium salts.... but for some reason NaOH is harder to find ...unless you work in a lab.

I just found it on Walmart.com, in 1, 2, 5, 10, 20 lb. quantities. Thanks for the tip!

 

[jviss]

Another tid-bit. The active ingredient in Drain-O is potassium hydroxide (KOH). You can get it cheaper than Drain-O online through Walmart...

Potassium Hydroxide (KOH),90% pure, Caustic Potash, Organic Soap making 6 Lbs (Pounds) - Walmart.com

Buy Potassium Hydroxide (KOH),90% pure, Caustic Potash, Organic Soap making 6 Lbs (Pounds) at Walmart.com

www.walmart.com

OR if you have another source for KOH that will also work. What you really need is the -OH part of that salt... so sodium hydroxide (NaOH) will work even better because sodium salts are more water soluble than potassium salts.... but for some reason NaOH is harder to find ...unless you work in a lab.

Will this stuff damage an asphalt driveway?

 

[rgranger]

Will this stuff damage an asphalt driveway?

I don't think so but you might want to test it on a small spot first.

Another thought....The homemade peel away works very well but it only works while it is still moist. The commercial peel away has you put a sheet of wax paper over the paste to keep it moist longer. I have found that you can gently sprits the homemade stuff with a garden hose to re-wet the paste once it dries... But since you are making a 5-gallon bucket of the stuff... just pressure wash off the bottom and if you have a stubborn spot, you have left over stuff in the bucket... so go again. I've done this at least a dozen times. If you have a roller on a pole it is easiest. Roll it on in the evening and pressure wash it off in the morning.

BETTER LIVING THROUGH CHEMISTRY

 

[LeeandRick]

Just going back and looking at the pictures you appear to have an old barrier coat under the paint like I had. Sanding or blasting is the only way to remove an old epoxy barrier coat. I tried all types of remover ideas and nothing worked.

 

[withintheruins14]

Just going back and looking at the pictures you appear to have an old barrier coat under the paint like I had. Sanding or blasting is the only way to remove an old epoxy barrier coat. I tried all types of remover ideas and nothing worked.

I appreciate that observation @LeeandRick. I'm curious, are you suggesting that the white layer I'm revealing isn't gelcoat but instead an old epoxy barrier coat?

 

[withintheruins14]

Still hoping to hear back from ya @LeeandRick

 

[Davidasailor26]

Hard to tell from the picture whether you’re exposing gelcoat or an epoxy barrier. Can you tell if there’s a ledge of built up barrier coat at the waterline, or does it look like the edge is just paint? Either way I don’t think it makes much difference. If it’s a barrier coat you don’t need to remove it. You can still coat right over it as long as it’s sanded and roughed up.

 

[withintheruins14]

Hard to tell from the picture whether you’re exposing gelcoat or an epoxy barrier. Can you tell if there’s a ledge of built up barrier coat at the waterline, or does it look like the edge is just paint? Either way I don’t think it makes much difference. If it’s a barrier coat you don’t need to remove it. You can still coat right over it as long as it’s sanded and roughed up.

Thanks for your time @Davidasailor26, I really appreciate the direction of both you and @LeeandRick's observations, because I had been having doubts about that white layer myself. To follow up, I will:

1. photograph the paint "ledge"
2. take some good photos of the "white" (gelcoat/barrier) layer

 

[withintheruins14]

@Davidasailor26, I've added close up pictures of the paint "ledge" and "white" layer. I added a few extra pictures to fill in the scene too. Is this "White" layer gelcoat or epoxy barrier coat? Thanks

Bootstrap Paint Ledge:

More Bootstrap Paint Ledge:

Keel Texture After Some Sanding and Acid - Any idea what color the iron is here?

Gelcoat or Epoxy Barrier Layer?:

 

[Davidasailor26]

I’m guessing you’re getting down to gelcoat, not any previous barrier coat. It doesn’t look like there’s any distinct edge at the top of it, and it doesn’t look like there’s any color change in the places it’s scratched through.

On the keel, I’m thinking the solid metal is the relatively smooth homogenous looking gray color in the top right of the picture.

 

[withintheruins14]

Thanks @Davidasailor26