Bottom prep advise on Steel Hulled Steamboat

[Mfoxchicago]

Ok Steamboaters, you have always been a source of council and good sense in the past. Perhaps now as well.

I am struggling with making an educated and correct decision on how best to proceed with prepping the bottom of my steel hulled steamboat. It is all so new to me.

It is a 30 yr old hull, well maintained and showing very little rust, superficial at the worst. However, she did sustain a bit of excessive jack stand wear during transport and some of the green anti-fouling is flaking off as expected. She is overdue of some sort of bottom refit. My use of her is a commercial venture and I hope to be able to leave her in a fresh water lake in western Texas for several years before I am needing to take her out for bottom work. No travel lift out in these parts, $2K each time I have to lift her out via a crane service.

Under the anti-fouling is a black epoxy primer application. Seems very durable. The previous Captain reports it to be an auto body grade Epoxy Frame Paint. Several of the oil field steel service outfits are recommending an epoxy primer called - Phynicon-HS.

I am being advised that I should Orbit sand the anti-fouling off, also any areas showing bare metal - then patch the areas that need new primer, then paint with a new anti-fouling.

I am concerned if this will provide my hull with the proper protection to serve her well for several years. Your thoughts.......

Also, does anyone have experience using a West Marine product called - Aqua-Strip - an ecofriendly stripper to strip old anti-fouling, perhaps saving me many hours of sanding?

I look forward to hear what experiences other have had with bottom work on steel hulls.

Thanks.

[johngriffiths]

Do you have access to an ultrasonic thickness tester? They can help give an overall view of condition Corrosion is sometimes very localised on steel hulls. One boat owner I know resorts to using the heads of 6" wire nails as rivets to plug small holes whilst the larger are filled by inserting patches which are welded in. If you apply patches to the surface here the boat will fail survey. The usual way to strip paint is by sand blasting followed very quickly (before the steel surface oxidises, it develops a dark bloom) by two pack paint in several layers. Is there nowhere you can pull it out using a trolley or two linked?

John G

[TahoeSteam]

Mack,

I will talk to a friend of the family that had another steel steamboat that was built by the Millerick bro's and see what he can suggest.

[Lopez Mike]

I'd just sand off the existing antifouling using an orbital sander hooked to a shop vac. Also sand the rusty spots. Then roll on another coat of the same epoxy autobody primer as is there now. Epoxy is great stuff. I've had better performance from epoxies than I ever had from red lead primer which was the old gold standard.

Do the new epoxy primer right after you sand the rusty spots.

I would ask around the best bottom paint for your local conditions. Each body of water has its own problems.

[gondolier88]

Hi,

Firstly, if you are on freshwater, depending on the average water temperature, you should not require antifouling of any sort; just an unnecessary expense- on many freshwater lakes, especially if they are reservoirs; it is banned anyway, so this may be worth checking.

DO NOT sand antifouling- it is seriously nasty stuff, and relatively small amounts can cause long term neurological problems. Although a large outlay, a good sandblasting co. will blast, prime and paint an entire hull in less than two weeks, you don't mention size, but anything between 50-70ft loa would be around a week to blast/prime/paint. It is the quickest (hence cheapest) option, and the only way you can safely say every inch of platework has been inspected- depending on your commercial use, your regulatory body may specify a platework inspection and it's helpful to have bare plates for them to look at, especially in problem areas where body filler may be hiding a multitude of sins...

Epoxy is definitely the way to go for primer- and in my experience (90ftx15ft steel steam yacht) the best top coat is an epoxy based flexible industrial paint system too.

We use International Industrial Marine paints, not cheap, but they are incredibly tough, easy to apply (can be rollered on by hand if you want to topcoat yourself).

Greg

[gondolier88]

Hi,

Firstly, if you are on freshwater, depending on the average water temperature, you should not require antifouling of any sort; just an unnecessary expense- on many freshwater lakes, especially if they are reservoirs; it is banned anyway, so this may be worth checking.

DO NOT sand antifouling- it is seriously nasty stuff, and relatively small amounts can cause long term neurological problems. Although a large outlay, a good sandblasting co. will blast, prime and paint an entire hull in less than two weeks, you don't mention size, but anything between 50-70ft loa would be around a week to blast/prime/paint. It is the quickest (hence cheapest) option, and the only way you can safely say every inch of platework has been inspected- depending on your commercial use, your regulatory body may specify a platework inspection and it's helpful to have bare plates for them to look at, especially in problem areas where body filler may be hiding a multitude of sins...

Epoxy is definitely the way to go for primer- and in my experience (90ftx15ft steel steam yacht) the best top coat is an epoxy based flexible industrial paint system too.

We use International Industrial Marine paints, not cheap, but they are incredibly tough, easy to apply (can be rollered on by hand if you want to topcoat yourself).

Greg

[Lopez Mike]

I sand my sailboat bottom paint once in a while with the blessings of the boat yard BUT I have my shop vacuum hooked to the sander and I wear a simple mask over my mouth and nose and a plastic tarp on the ground. This presupposes that you are lucky enough to not have any tributyl tin paint on the boat. That requires special masks that protect your eyes as well. If you are dealing with simple oil based copper paints, you can be safe with common sense precautions. Not nearly as bad as lead stuff in old houses. Yuck.

Another solution if the existing paint is still working is to use a scotch bright pad and a hose to just remove any dirt, plants and animals so that a fresh coat will bond well. I only sand when the buildup of old paint is so thick that it is starting to flake off. Don't mess with what is working.

Whether you need antifouling depends on the lake (and, of course, local regulations!). Are you drinking this water? We have several lake steamers here in the Northwest but most of them are trailered. I would ask the locals at the lake where you are going to steam. I have seen some pretty hairy looking bottoms on lake boats. Given the cost of haul outs that you quote, I would investigate carefully. Talk to the pontoon boat people rather than the wake board, jet ski and speed/noise lunatics. The pontoon boats are moving at your speed and they are often left in the water a lot.

At five knots you don't need a racing bottom.

[Mfoxchicago]

Hey Guys, great advise from all of you. I am very grateful!

{Whether you need antifouling depends on the lake (and, of course, local regulations!). Are you drinking this water? We have several lake steamers here in the Northwest but most of them are trailered. I would ask the locals at the lake where you are going to steam. I have seen some pretty hairy looking bottoms on lake boats. Given the cost of haul outs that you quote, I would investigate carefully. Talk to the pontoon boat people rather than the wake board, jet ski and speed/noise lunatics. The pontoon boats are moving at your speed and they are often left in the water a lot.

At five knots you don't need a racing bottom.}
Thanks Mike. Nice way of looking at this. Yes, this lake does eventually feed water downstream to our main Municipal Water Intake supply. Avg. water temps would be in the 70's or higher and I am unaware if ANY other boats on this lake in these parts use any other bottom treatment other than bare aluminum pontoons or factory gel coat. I'll save the money.

{DO NOT sand antifouling- it is seriously nasty stuff, and relatively small amounts can cause long term neurological problems. Although a large outlay, a good sandblasting co. will blast, prime and paint an entire hull in less than two weeks, you don't mention size, but anything between 50-70ft loa would be around a week to blast/prime/paint. It is the quickest (hence cheapest) option, and the only way you can safely say every inch of platework has been inspected- depending on your commercial use, your regulatory body may specify a platework inspection and it's helpful to have bare plates for them to look at, especially in problem areas where body filler may be hiding a multitude of sins...

Epoxy is definitely the way to go for primer- and in my experience (90ftx15ft steel steam yacht) the best top coat is an epoxy based flexible industrial paint system too.}

Thanks Greg. Sandblasting, while available here, it would be problematic in moving the boat to the contractors facility (15 miles further away from the lake w/ additional load permits & escourts), plus doing the blasting at the current site would probably raise red flags about contaminating the surrounding cotton farmer's crop with blast residue - really, they are very fussy about their cotton crops out in these parts.

I am looking at using Westmarine's Aqua-Strip Biodegradable paint stripper to pull off the antifouling (anyone have experience with this product?), look at what condition the epoxy primer application is in, sand out any corrosion or rust I find, then epoxy the entire hull in the newer base color ( gray or white ) are the options. The local steel tank guys are saying something called Phyinicon-HS made by Sherwin Williams can handle anything thrown at it (fracking water/oil separating towers).

I am frustrated being out in fiberglass boat country with no established boat yard around to get assistance from. Your council and advice means a great deal to me. Thanks guys.

[Billsteamshovel]

While new to steam I've had heaps of experience with epoxy and steel boats.
Others have made the point re anti foul and fresh water, but if it were me I'd sand the entire hull below the water line to remove the anti foul - with the right safety gear, but don't go through the two pack epoxy. Then I would spot sand the parts where you think the coating has been breached or failed back to bare metal.
Then spot prime with the same two pack as perviously used straight onto bare metal as soon as you finish sanding.
No point sanding off good epoxy as its really expensive and in fresh water will last for years.
Hope this helps.

Wes