Post Process After Soda Blasting Bottom

[snoopy_]

Hello,

I am going to have my bottom soda blasted and was wondering about what I am getting myself into. I assumed that I would have some work to do after the soda blasting, but not sure how much work is actually involved. I thought at a minimum I would have to sand the bottom, maybe multiple grits, then a few coats of barrier paint, followed by a few coats of bottom paint. But now I have a lot of questions.

1. For a 1990 Catalina 30, what is the likelihood there I have to worry about blistering? I bought the boat last spring, so no idea how it was used before me.

2. Should I apply barrier coats? If so, how many? What type should I use?

3. I will have to apply some sort of bottom paint because it will be in saltwater, but what type? Hard, ablative? How many coats?

Thank you,
Snoopy

 

[Captain Larry-DH]

1) If you have blisters it will show. Treatment- there is lots of information about it on the web
2) 2 coats of barrier coating is standard. Use any brand and follow manufacturers directions
3) There‘s no single “best” paint. There are many brands of bottom paint that are good. Practical sailor does testing, but those tests are static samples immersed at a dock, and might not apply to a moving boat in your area. Choosing a paint involves many considerations. Effectiveness, whether you race or cruise, ease of application, or environmental “eco” impact, water based vs. solvent based, hard vs. soft ablative, etc.
Different areas have different fouling issues, so ask your local divers or or boatyard about which types they recommend. And research the pros and cons.

 

[jssailem]

You may find the need to fair the hull. Use a good Epoxy filler to fill any small areas.
You may need to add fiberglass cloth if there are blister holes.
Follow up with a barrier coat as indicated by @Captain Larry-DH

Follow directions on all fillers.

This information may aide you in dealing with blisters. Hull Blisters on Boats and Yachts - by David Pascoe, Marine Surveyor

 

[MikeHoncho]

Has the blaster seen the hull? I’m curios is soda will eat through that.

 

[Captain Larry-DH]

Has the blaster seen the hull? I’m curios is soda will eat through that.

No problem.

 

[Ward H]

I've looked closely at 89, 93 and 95 C30s. No evidence of blisters.
In our marina Petit Hydrocoat ablative paint is popular. One fresh coat each spring does the trick.

 

[Captain Larry-DH]

@Ward H I‘ve been using Hydrocoat at least 10 years, and agree it’s a good paint. Low VOCs and easy to use. @snoopy_ if you get Hydrocoat, I recommend the SR version, with Ergerol, it is more effective against slime. Have tried it with and without Ergerol, and it’s worth the extra cost, IMHO.
I have heard Hydrocoat Eco is less effective than the original Hydrocoat, but haven’t had personal experience with it.

 

[Closing Time]

I have been where you are several times before. You are on the right track. First, by a moisture meter. I got a $50 one from General Tool and used it alongside a high dollar model on recent survey of our new to us 310. Works great.
First make sure you deal with the blistered areas by grinding them out, drying them out and filling with epoxy. Second, once the entire bottom is dry and filled, I sanded with 40 grit in a 8” wheel angle grinder. Did I mention protective equipment? This stuff is all highly toxic.
Third, I hired a guy with a steam power washer to get the bottom really clean. Dry again.
I rolled eight coats of Interprotect 2000 barrier coat as I knew I would be in the water for about 10 years with no haul out. Then when the barrier’s last coat was dry but before needing to sand prior to revisiting, I rolled three coats of Petit Trinidad hard bottom paint. When that was dry, I followed with 3 coats of West Marine ablative. Ten years later, no blisters and she needed a bottom job but we made the 10 years. Freshwater Oklahoma lake with no lift. 41’ Islander Freeport 41.
I bought the Catalina 25 across from me that had also not been out of the water for 10 years. Interprotect 2000 on her and no blisters either. 2000 is great stuff.

 

[Justin_NSA]

Pay attention to recommended application temperatures. This time of year they may not cure correctly and the process could get botched.

 

[Whatfiero1]

For the cast iron keel I used osphoric acid to prep the steel prior to the epoxy paint install. read the spec on painting times and temperature it needs to be followed for good adhesion

 

[Justin_NSA]

I wish our Hunters had lead keels like the C30s !

 

[Don S/V ILLusion]

I wish our Hunters had lead keels like the C30s !

Most Hunters do (have a lead keel)... Why Hunter produced the H30 with an iron keel is curious.

 

[Justin_NSA]

Most Hunters do (have a lead keel)... Why Hunter produced the H30 with an iron keel is curious.

I assumed it was the other way around. The H25.5 next to me in the yard is cast iron too. So is the H28.5 in the other yard.

 

[snoopy_]

Pay attention to recommended application temperatures. This time of year they may not cure correctly and the process could get botched.

I do not intend to tackle the barrier and bottom paint until closer to spring. I live in the Philly area and I thought it'd be too cold until April.

For the bottom and barrier, the soda blaster provided local knowledge for Cape May, NJ. as follows:

Interlux:
Interprotect 2000 followed by two coats of the Micron products.Micron CSC.

Petit:
Pettit protect followed by Vivid

 

[Closing Time]

I am getting ready to do the same thing on a new to me 2004 Catalina 310. I live in Oklahoma and our weather gets above 60 for stretches in March or so. The yard here in OKC likes the Sherwin Williams barrier coat better than Interprotect 2000. Days it was developed for commercial use. I have used Interprotect on three previous boats in fresh water and no problems at all after 12, 16 and 10 years.
This time I am going to do the following:
1. Soda blast or steam pressure wash and remove old paint. It’s already off the keel and rudder from survey wash down.
2. Grind out a few blisters.
3. Let dry. If there’s not many, I may assist with a heat gun.
4. sand and de wax again.
5. Power wash again.
6. Dry.
7. I think they want 20 mils of barrier. I’ll take the yard recommendation of SW as that’s what they use.
8.Three coats Interlux Ultra for “Base Coats”.
9. Yard uses Interlux VC 17 two coats over Ultra. Says you can scuff it up every year or two and roll another coat for remainder of your life and you are good to go.
17 goes on thin and you can launch in 20” it says. Sounds promising to me.
Good luck!

 

[snoopy_]

Soda blasting is done, unsure of the next step.

I figured I would need to sand with some 80 grit, wash it, clean it with acetone, then apply the barrier and then bottom coat. However, there are some small chips in the hull, and I was wondering if you think it needs a fairing compound first? I am not a racer, just cruising the Atlantic coastline of New Jersey for day sailing.

I was looking at using TotalBoat Fairing Compound if needed, which was recommended as it's easy to apply, forgiving, and easy to sand when dried/cured. I plan to follow that with Pettit Protect barrier, and Pettit Hydrocoat for the bottom.

How much fairing compound would be required to fair a Catalina 30’?

Any

Any advice would be greatly appreciated.

Mike Montone

 

[sailme88]

I had set out to soda blast our hull 4 years ago.. Hired a young man that stared me away from soda and onto glass bead. He had references from several marinas.. Did an outstanding job.

 

[jssailem]

How much fairing compound would be required to fair a Catalina 30’?

That is a loaded query. Depending on your boat you can start with a quart but be ready to buy the gallon. Jamestown Distributors had some sales running. I think one of the BoatToday videos covered the fairing process. I think Andy was using Total Boat fairing compound.

 

[sailme88]

Soda blasting is done, unsure of the next step.

I figured I would need to sand with some 80 grit, wash it, clean it with acetone, then apply the barrier and then bottom coat. However, there are some small chips in the hull, and I was wondering if you think it needs a fairing compound first? I am not a racer, just cruising the Atlantic coastline of New Jersey for day sailing.

I was looking at using TotalBoat Fairing Compound if needed, which was recommended as it's easy to apply, forgiving, and easy to sand when dried/cured. I plan to follow that with Pettit Protect barrier, and Pettit Hydrocoat for the bottom.

How much fairing compound would be required to fair a Catalina 30’?

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Any advice would be greatly appreciated.

Mike Montone

Whatever barrier coat that you go with do your homework on the application process. I had used System 2000 by Interlux. It was saying 4-6 coats. Went with 4. Started with gray, then white, back to gray, ending with white. Then when the last white coat was still tacky, the first Alblative coat blue followed by a red coat...

 

[snoopy_]

That is a loaded query. Depending on your boat you can start with a quart but be ready to buy the gallon. Jamestown Distributors had some sales running. I think one of the BoatToday videos covered the fairing process. I think Andy was using Total Boat fairing compound.

I figured it'd be loaded, not knowing how how many dips and chips there'd be, which would equate to how much compound would be required/used. I think I may by two quarts just in case, to be sure that I have them on hand, no need to re-order, etc. I was concerned whether I should epoxy the chips first, then apply fairing compound, etc. so I wrote to Pettit as well asking advice. They replied with: Sand, clean with Pettit 92 Bio-Blue cleaner, fair, two coats of the Pettit Protect, two coats of the Hydrocoat or Odyssey antifouling.

Having never done this before I am more than a little, but I am doing my research and due diligence. I also need to wait until a little warmer weather, and trying to gauge how long the process will take. I have some travel for work in May, so I would like to complete this work in April, launch the boat in April, and reposition the boat to it's new seasonal marina about 100 nm away.

Thanks,
Snoopy