Bottom Painting 15-footer

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
alan-bc
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Joined: Tue Jun 29, 2021 7:13 pm

Bottom Painting 15-footer

Postby alan-bc » Sun May 29, 2022 8:49 pm

My recently purchased c.1980 SPORT 15 is my first power boats. I believe the hull has six coats of bottom paint--that's how many different paint colors I can see in various scrapes and scuffs. The paint appears to be applied many years ago.

I want to apply new bottom paint correctly: sand down to gelcoat; apply an epoxy base coat; apply decent bottom paint.

Q1: how do I get to the bottom of the hull?

Q2: how can a c.1980 SPORT 15 be lifted off its trailer without damage to the hull?


I have no idea what the old Whaler will tolerate.

Q3: to what can I attach the lifting cables?

Q4: can a c.1980 SPORT be lifted using the stock rigging hardware?

Q5: are nylon belly straps an option?

All replies will be appreciated.

BACKSTORY
When I was still a sailor, the answer to how to apply bottom paint was easy; sail to somewhere with a lift, pay money for darn near everything.

Surely I can lift the SPORT 15 boat off the trailer, pull the trailer out, work on a mechanic's creeper, and do a nice bottom painting job. My thought was to pick the back end up with an engine hoist, and lift the front with a chain hoist attached to the beams in the car port. Once up, pull the trailer out and set the boat back down on some stands with the two hoists still connected; belt and suspenders-like.

Alan

ConB
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Re: Bottom Painting 13-footer

Postby ConB » Mon May 30, 2022 1:36 am

Use the two lifting eyes on the inside of the transom and the one eye inside at the bow for a three point lift.

I would take it a step further:
  • and remove the engine and loose stuff from the boat
  • get a case of beer
  • invite over three or four friends
  • flip the boat upside down
  • remove bottom paint
  • repaint.
Con
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jimh
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Re: Bottom Painting 15-footer

Postby jimh » Mon May 30, 2022 7:53 am

The eponymously named lifting eyes are intended to support the boat from an overhead suspension. Keep the lifting cables vertical as much as possible to reduce lateral forces on the hull.

CON's method will allow the considerable work needed on the hull bottom to be more easily done.

The anti-fouling paint you remove should be preventing from getting into your lawn or garden. The old paint may inhibit plant growth.

If you really plan to get the hull down to the gel coat layer, you might want to assess the need for applying bottom paint. Unless the hull is going to be continually in the water and the water is known to have rapid marine growth, you may just need a bottom sealing coat. If the SPORT 15 is going to live on the trailer and only see use in the water for a day or two at a time, you probably do not need any bottom paint or sealing coat.

By the time you abrade away all the paint and get to the gel coat, I expect that the gel coat surface may be rather rough. The degree of roughness in the gel coat will depend on how the original layer of bottom paint was applied. If the gel coat was not intentionally sanded to a rough finish prior to the first coat, the gel coat could be still in sufficiently decent shape to buff it back to a gloss finish.

Advice from Boston Whaler about bottom paint is given in the owner's manual. If you do not have an owner's manual, you can read my HTML version of the factory owner's manual that I published many years ago. It is in the REFERENCE section. See

https://continuouswave.com/whaler/reference/manual9-17/

ASIDE: as a reformed sailor myself, congratulations on getting a Boston Whaler SPORT 15. The SPORT 15 is perhaps the finest small boat ever made. In my own evolution to power boating from sailing, a SPORT 15 was my first power boat.

alan-bc
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Re: Bottom Painting 15-footer

Postby alan-bc » Fri Jun 10, 2022 6:21 pm

ConB wrote:Use the two lifting eyes on the inside of the transom and the one eye inside at the bow for a three point lift.

I would take it a step further:
  • and remove the engine and loose stuff from the boat
  • get a case of beer
  • invite over three or four friends
  • flip the boat upside down
  • remove bottom paint
  • repaint.
Con


Good idea, flipping it over, and in fact, one I had been considering. But getting the motor off and separated; not something I wanted to do. Not that I think it's beyond my capabilities, but it sure seems like a lot of work. But if I disconnect nothing at the engine, if I simply leave everything attached to the engine and remove it at the other end, this might be not so bad.

As to inviting 3 or 4 friends over, that's sadly not an option.

But I might be able to pick it up at the bow and stern, remove the trailer, lower the stern and with suitable rigging, rotate it all by myself.

That might be a plan.

Thanks again for taking the time to respond.

alan-bc
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Joined: Tue Jun 29, 2021 7:13 pm

Re: Bottom Painting 15-footer

Postby alan-bc » Fri Jun 10, 2022 6:51 pm

jimh wrote: If the SPORT 15 is going to live on the trailer and only see use in the water for a day or two at a time, you probably do not need any bottom paint or sealing coat.
Nope, that's not the plan. I find myself in the incredibly fortunate position of having ocean-front property with a deep water dock. I had to move to the middle of nowhere to get this, but I'm pleased about doing so every single day.

My sailboat lives on one side of the dock, the Whaler will live on the other, for about four months of the year or so, I expect.

Pulling it out of the water last year after just a couple of months, there were dozens and dozens of barnacles. I pressure washed as best I could while on the trailer, and got most of the evil things off, but certainly not all of them. So bottom paint is sadly called for.

Thanks for this, as I don't have a manual! My Whaler is so old, if it even came with an owner's manual, it would have been written with a quill pen.

jimh wrote:ASIDE: as a reformed sailor myself, congratulations on getting a Boston Whaler SPORT 15. The SPORT 15 is perhaps the finest small boat ever made. In my own evolution to power boating from sailing, a SPORT 15 was my first power boat.
When I went looking for a power boat last year, I had exactly two to choose from within reasonable driving distance, both well used. One was a whatever with a noisy smoky OLD 2-stroke, the other was the Whaler with a newish EFI Mercury. Easy choice, even if I overpaid for the Whaler, as I'm sure I did. But overpriced or not, I'm very pleased with the boat, very pleased indeed.

And it has that big advantage that all old boats have; drilling a hole or two to add your own something doesn't raise the blood pressure. Drilling a hole in a brand new boat. As an inveterate tinkerer, this is a huge plus.

A famous sailboat designer once mused "if life should so conspire that I could do only one thing, sail a boat or work on a boat, I think I would choose to work." I actually feel much the same way.

Thanks for the detailed reply--Alan

dtmackey
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Re: Bottom Painting 13-footer

Postby dtmackey » Mon Jun 13, 2022 8:11 am

alan-bc wrote:Q2: how can a c.1980 SPORT 15 be lifted off its trailer without damage to the hull?
Just use the 3 points on the hull (bow and stern eyes)

Image
Fig. 1. Lifting with three points

alan-bc
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Re: Bottom Painting 15-footer

Postby alan-bc » Thu Jun 23, 2022 11:28 pm

dtmackey wrote:Just use the 3 points on the hull (bow and stern eyes)
Thanks, that's what I've done. But being chicken, I removed the seats, the outboard and the console--everything, really--to get the weight down as low as I could.

I then used an engine hoist on a stern eye to lift one side, rotating the hull 75-degrees. I was then able to scrape and sand one side while standing. Next day, I rotated the other way and did the other half.

Tomorrow, all going well, I'm going to flop the boat over 180 degrees for painting. To do so, I've fabbed up a plate with a post in the middle. The plate will bolt to the outboard motor holes (with suitable correction for their off-centeredness).

I'll loop some webbing around the post and lift it with the engine hoist.

It should be a simple matter then to rotate it by hand as it dangles from the post.

dtmackey
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Re: Bottom Painting 15-footer

Postby dtmackey » Fri Jun 24, 2022 1:27 pm

alan-bc wrote:Thanks, that's what I've done. But being chicken, I removed the seats, the outboard and the console...


If you are flipping from upright to upside down, this can be done by one person, now that you've removed all the weight from the boat. I've done several 13-footers over the years. I place pads on the ground and lift on side, balance upright while moving to the opposite side and then lower it down holding onto the gunwal. A 13-footer is only 320-lbs or less when stripped, and you have no more than half the boat weight when flipping.

alan-bc
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Re: Bottom Painting 15-footer

Postby alan-bc » Fri Jun 24, 2022 3:25 pm

dtmackey wrote:Just use the 3 points on the hull (bow and stern eyes)
Sadly, this is good advice only if the [lifting] tackle is in good repair. Mine obviously wasn't.

My Boston Whaler boat came smashing down onto the concrete of the carport from about 4 feet high. If I ever do get it inverted, I shudder to think what I might find.

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alan-bc
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Re: Bottom Painting 15-footer

Postby alan-bc » Fri Jun 24, 2022 3:38 pm

dtmackey wrote:If your flipping from upright to upside down, this can be done by one person, now that you've removed all the weight from the boat.
This 15-footer is a waterlogged 15. Based on how hard my engine hoist has to work to lift just the back end, my best guess [is the weight of the hull now] is 600 to 700-lbs.

Sadly, while these are supposed to be foam filled, I've discovered that the foam, on mine anyway, has pretty much given up the ghost.

There's been a number of holes drilled in the hull to mount things. The fuel tank, the hinges for the front hatch. I decided to drill them out to about 5/8-inch, undercut a bit, plug the hole with thickened epoxy, then reattach. Well, every place I drilled was hollowness below. No foam whatsoever. Maybe the old Whalers used water soluble foam, I don't know.

But even though I've got about $1,000 worth of brand new bits to go on this boat as part of the restoration, I'm five minutes away from posting a "free to haul away" ad on Craigslist.

jimh
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Re: Bottom Painting 15-footer

Postby jimh » Sun Jun 26, 2022 8:12 pm

The six coats of existing bottom paint may have hidden some flaws which might have been revealing of the hull's true condition.

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Phil T
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Re: Bottom Painting 15-footer

Postby Phil T » Mon Jun 27, 2022 11:58 am

Do NOT sand off the bottom paint as it may be toxic. You could harm yourself, contaminate your yard or your neighbor's.

There are high strength non-toxic strippers available.

Peel-Away has very good reviews. Wear protective clothing/gloves/respirator.
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jimh
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Re: Bottom Painting 15-footer

Postby jimh » Tue Jun 28, 2022 10:16 am

alan-bc wrote:... while [Boston Whaler boats] are supposed to be foam filled, I've discovered that the foam, on mine anyway, has pretty much given up the ghost.
A Boston Whaler Unibond hull has high density foam that was injected and expanded against a closed mold, with only a few small vents to permit excess foam to exit the mold, and originally would have completely filled the interior space--assuming the boat was correctly molded and foam-filled. Boston Whaler routinely checks all hulls after the molding and foam filling for evidence of any air pockets or voids in the structure. The bond between the foam and the laminating resin is a primary bond, made as both materials cured while in contact and under pressure, resulting in a very strong and durable bond between them.

Intrusion of water into the foam can occur. If water gets into the foam, and the boat is kept in a cold winter climate, the freezing of water trapped in the foam can cause the foam to be crushed, creating more space for water to intrude and occupy more of the interior volume. Next winter when that water freezes and expands it causes more damage.

Problems with the foam interior are often reported, but they are by no means universal to all hulls ever made. It is quite reasonable for Boston Whaler boats of more than 20-years-old to still have hulls with minimal--if any--water intrusion and with dry foam interiors.