Time to call it good enough

[Howard]

Good information Paul. I used the S3 water based LPU on the Spindrift. It has held up, but has been lightly used and not abused....and still....contact with a concrete loading ramp skinned it pretty good. Certainly not nearly as durable as gelcoat on a plastic boat would be. I've had a sample piece of painted plywood out in weather going on about 3 years now. It has held up, but hasn't been moving or subject to abuse. (Edit: I just checked and this piece has problems. I'll find and update my rot test thread). Just weather. On real "varnish", I've never tried that over epoxy. Only bare wood. For epoxy coatings, I've used Interlux Goldspar, described as a poly, but which now that I look, also says "alkyd" on the can. It has held up well. Like sugar in food, amazing how they sneak it in there! 

Has anyone ever tried automotive paints? The guy who built my "classic plastic" recommends this to the exclusion of all others. An epoxy primer covered by an automotive paint.

Curious how this might work on an epoxy sheathed/coated plywood boat? Or given all the variables, what is the best choice? The main criteria for me would be appearance and durability....survives abuse.....and longevity. How long should a good paint job on epoxy sheathed boat last?

[Bud_Wilson]

Most of you know my thinking on paint,but I am going to post it again. Outhouse paint for outhouses, poarch paint for porches, car paint for cars, Boat paint for boats. Bud

[Ken_Potts]

  My rule is slightly different.  I built the boat on my porch so I figure I can use boat paint or porch paint.  Now, If I had built it in the outhouse...

[PAR]

Automotive paints have changed a lot in the last decade, which type of paint is he referring to?

As a rule you can use automotive paint any place that could use an LPU successfully. The surface must be stable, very stable or it will have the same issues as LPU. Most automotive paints are LPU's but more sophisticated then marine paints. These are often 3 and 4 part paints with costs that match. I suspect your classic plastic builder is just trying to get you to use what he's most familiar with, which isn't always the wise choice. Paints have become quite specialized and you need the one that fits the application, not the the gun swinger's comfort zone.

[Howard]

"Swinging" from memory, but I believe it was a LP called Deltron (ppg). Also said its probably now baned in all 57 states (little joke there for those of you with sense of humor). I doubt auto paints are cheap, but also do not carry the additional weight of that "old marine markup".

Automotive paints have to survive the sun, flexing and movement....I presume the metal on a car body does a little expanding and contracting due to temps? But again, I have no experience with them on something like plywood. I have been tempted to prep a little plywood box and take it to an auto rebuilder I know and let him shoot it with leftovers if he ever runs long someday. I'd put that outside, treat it poorly and watch it weather.

[PAR]

I'm very familiar with the Deltron line and if you want to screw around with the six or seven different reducers, hardeners, special cleaners, etc. then go for it. As a rule the LPU's will only be effective over stable substrates. Yes, metals expand and contract, but not even close to the amount non-encapsulated wood will. In other words, wood can swell a piece 10% dimensionally, but metal may grown less then a single percentage point.

The plywood box outside is a good idea, but also remember to flex it regularly, to simulate hull distortions under load or the slamming loads of a powerboat as it crashes off a wave, not to mention float it in nasty water for a weekend every so often, so it's a fair boat test, not an example of how a park bench might fair with this paint.

[Howard]

Yes, metals expand and contract, but not even close to the amount non-encapsulated wood will. In other words, wood can swell a piece 10% dimensionally, but metal may grown less then a single percentage point.

For clarification, we are talking a plywood coated boat here right? Perhaps even coated by one or two layers of glass cloth? I was under the impression those were dimensionally stable. Not totally, but pretty much so.

BTW, since you mentioned powerboats. What type of paint finish do they use on those offshore plywood fishing boats?

(And apologies to Daniel for hyjacking his thread. Paul is trying to teach me and I'm learning slow).

[Daniel Gross]

No worries, Howard.

Learnin's good

Dan

[PAR]

Simply put, automotive paints are generally less flexible and have fewer additives then marine versions of the same stuff. On the other hand, industrial coatings are usually just as tough as marine, often better in some regards.

Paint selections are nearly as diverse as girl friend choices. An offshore fishing boat can fall into several categories, any of which would require a different paint. Most commercial craft will opt for the durability end of the spectrum and don't really care about color options, ease of application or gloss retention. If they could get away with no paint they would. Commercial craft run the full spectrum of porch enamel to truck bed liner.

Pleasure craft desire much more from their paint selections, with looks, ease of application and gloss retention high on the desirability scale in comparison to commercial.

Yes, LPU's are acceptable on well coated and sheathed boats, but don't let this finish get "away" from you, with age, damage, maintenance, etc. or it'll cause you to cuss it's invention.

[Daniel Gross]

Been busy this weekend, got the mast and boom cut out and tapered it was a chore but not as bad as the bowspirit in my opinion.

I don't have a table saw or a band saw so everything has been done with hand tools, electric and me powered, I like the me power better :grin:

The taffrail wasn't that bad, still have a little to do on it though I'm going to let it set in place to really remember it's shape before I pull it off to

shape it some more, the heat gun trick worked pretty well to get it to bend.

I'm going to 45 the corners of the mast tomorrow if it doesn't rain, backing up a bit I cut the mast out of a 4' and a 12' df 4x4 it probably would have

been easier to do a single 16' but transporting it would have given me a stroke, it was bad enough with inattentive drivers behind me with only 4' sticking

out of the truck bed  :x

Getting the two pieces to match up just so was interesting but doable.

Here's some pics

Taffrail

Bowspirit

Mast and boom

Thanks for the help

Dan

[Daniel Gross]

Hi guys,

I need some advice on spar finishing, the mast and boom and soon the gaff will be ready for finishing and my question is what to use.

Everything is douglas fir and I want the grain to show but I'd like the spars to be much darker than natural fir.

I'm going to epoxy and either varnish or clear coat them.

Hope that's clear enough.

Thanks in advance.

Dan

[PAR]

Use a water based stain on the raw wood, but make sure it's just a stain, not a stain/sealer, which is very commonly found in hardware store type of stains (MinWax). Go to a real paint store and get just a stain.

You could also tint the epoxy instead of using a stain. These are available from most paint stores as a dry acrylic pigment. I prefer this better then stain, though you will have to mix your own color. Douglas fir will darken considerably when you apply epoxy and again when you apply varnish, so do some test pieces before you commit to a stain or tint.

[Daniel Gross]

Thanks Par,

I'll start a few test pieces tomorrow and see what they look like.

Dan

[Al Stead]

So, what's with all the black weekenders this year?  I just said "good enough" to my paint job on the hull and am going to flip her back over tomorrow.  According to my count, this makes 4 black weekenders getting wet this spring, although it will probably be summer before  mine gets wet. 

Nice looking job though.  I hope mine can stand up to yours. 

Al Stead

[Daniel Gross]

Thanks Al,

We want pictures!! :grin:

Dan

[Daniel Gross]

Mast & boom update,

First coat of epoxy on and I'm I like how it darkened up.

I'm getting ready to apply a second coat, hope they get even darker.

Dan

[Daniel Gross]

Just got my gooseneck from Duckworks,

For those of you who have used it how did you attach it to the mast? The holes in the plate look a little

small to me, I'm thinking about drilling them out and using larger screws bedded in epoxy.

Any thoughts?

P.S. Did a little more painting yesterday.

[PAR]

I suspect that larger fasteners will just permit you to inspect the mangled, distorted mess after a catastrophic failure. The standard size fasteners will likely exceed the breaking strength of the gooseneck's weakest link.

[Daniel Gross]

Thanks, Par

Dan

[Daniel Gross]

A quick update,

it seems that the further along I get the slower I get, I think I'm thinking to much :shock:

anyway, the cabin and fore peak is painted finally had I thought about it before I put it all together

I would have painted as much as possible before assembly especially the under side of the deck :mad:

Oh well all sawdust under the bridge now.

Lots of sanding and varnishing

Lots of sitting and looking.

Have been working out the colors for the cockpit and deck, the hull and cabin sides are black and the rub rails

and hatches will be red, I am leaning toward a red cabin top and light grey cockpit and deck, it is currently

under much debate one wants just black and red, and one wants gold cockpit and decks.

It's a good thing I have final creative say in the matter :-D

With all the talk of mast box angle lately I thought I'd check mine, cause I don't have enough to do already!

I knew it was a little off after it was already too late to change it, I get ahead of myself sometimes.

It is at 98deg, 5deg off oh well guess I'll be cutting a wedge off my pretty mast base tomorrow while paint is drying

after laying it out on a spare 4x4 It looks like 5deg from the deck level of 21inches is about in the middle of the mast

base at the bottom, seems a little much, is this pretty close?

any advise appreciated, don't want the first sail out to be a flop.

Thanks Dan