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  #1  
Old 08-03-2010, 01:48 AM
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DennisRB DennisRB is offline
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Re coating tiller. What to apply?

I have sanded the old clear coat off a tiller. The coating was chipped in some areas and the coating was pealing off around the chips as water intruded. So whatever it was, it didn't stick real well. Also the wood was a little water damaged in those areas but I think I have the prep work nailed. I finished with 150 grit on a electric sander.

What type of clear-coat should I apply for a nice hard waring finish? Any tips on the amount of coats and prep between coats will be handy too.

This is not the tiller but it is of this style with the multiple layers and curve. What do you call this construction method?



Thanks guys.
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  #2  
Old 08-03-2010, 05:30 AM
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waikikin waikikin is offline
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Dennis, if you want it to stay nice the best thing you can get is a cover, with varnish there's plenty of opinions, I've had success with, Watsonia weatherproof(from the hardware store), International schooner, Altex. You might want to give it a hand sand to finish after the machine with the grain with 180, give it 6-8 coats with a wet sand in between or scourer, also use a tack cloth before recoating, "gearson" tack cloths are good, you get them from panel shop suppliers. Also to keep varnish nice, maintenance coats are required- sand 1 off- put 2 on maybe once per annum. The construction would simply be known as "glued laminated". All the best from Jeff.
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Old 08-03-2010, 12:07 PM
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gonzo gonzo is offline
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All varnish will eventually delaminate and chip. The UV degrades the bond between the coating and the wood fibers. A varnish with UV protection helps. You should recoat at least yearly.
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Old 08-03-2010, 04:15 PM
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DennisRB DennisRB is offline
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Thanks. The tiller does get covered. It probably lasted until now from 1987. I guess it was varnish then as what you describe Gonzo has happened with the chipping and delamination. It appears to have been chipped first then it delaminatates outward from the chip. Would coating it with epoxy laminating resin prevent the wood from getting damaged? I heard epoxy gets damaged by UV? What about polyurethane? What grade wet and dry should I use between coats?
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  #5  
Old 08-03-2010, 10:09 PM
missinginaction missinginaction is offline
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Both epoxy and and polyester based resins degrade from UV. Actually, just about everything degrades from UV exposure including people. Most people will tell you that multiple coats of varnish sanded lightly with, say, 220 grit between coats will give you a nice durable finish. You will have to recoat every year or two depending on how much sun the tiller gets.

If you're adventurous you might try one of the 2 part polyurethane based varnishes. I know that Interlux makes one called Perfection Plus and you can find out about it at:

www.yachtpaint.com

I haven't used Perfection Plus but I have used Interlux Perfection, which is the two part polyeurethane paint with really nice results. Since the paint performs exactly as the manufacturer claims I'd have no hesitation about using the varnish.

Good Luck,

MIA
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  #6  
Old 08-03-2010, 10:29 PM
mcollins07 mcollins07 is offline
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It's all the rage now. Paint with two or more coats of epoxy, such as West System; then two coats of Automotive Clear Coat for UV protection.
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Old 08-03-2010, 11:14 PM
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alan white alan white is offline
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I recommend varnish alone. It takes five minutes or less to recoat a tiller after three minutes of sanding. Chipping will occur with any coating including two part coatings. Varnish alone is easiest to repair in such a case.
I don't understand why there's such an emphasis on absolute last-forever-hard as a rock coatings when they are very difficult to touch up.
Varnish, ordinary tung oil varnish, is so forgiving and so practical, nothing else comes close.
Believe me, the best mahogany runabouts in the world, the Hackers and Chis Crafts and so on, are just about all varnished with tung oil varnish. They do spray large areas sometimes, but seldom with two-part polys. And they don't epoxy the wood first.
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Old 08-04-2010, 01:04 PM
missinginaction missinginaction is offline
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You've got my vote Alan. I'm adding some mahogany trim to the Silverton to break up the all white exterior. Just using multiple coats of varnish. Figure I'll just mask it off in a couple of years when I need to touch up.

The paint though, geez I really like it Alan. It's so hard that you really have to work to put a scratch in it.

MIA
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Old 08-05-2010, 09:25 AM
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alan white alan white is offline
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Quote:
Originally Posted by missinginaction View Post
You've got my vote Alan. I'm adding some mahogany trim to the Silverton to break up the all white exterior. Just using multiple coats of varnish. Figure I'll just mask it off in a couple of years when I need to touch up.

The paint though, geez I really like it Alan. It's so hard that you really have to work to put a scratch in it.

MIA
I agree back at you, MIA. Paint is a different thing altogether. My rule would be, match paint hardness to surface hardness. Soft surfaces like cedar, etc., should be painted with a softer paint (alkyd). Glass and hard surfaces, two part is better. Varnish is different in that it's always over wood, which moves a lot. Tung oil varnish can stretch to that movement very well. Hard formulas will crack or check sooner.
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Old 08-05-2010, 03:36 PM
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DennisRB DennisRB is offline
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How long do you have to wait between coats of varnish

A: to recoat without sanding?
B: to recoat with sanding?

Do I need to sand between each coat?

Thanks guys. Dennis.
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Old 08-05-2010, 03:57 PM
dskira dskira is offline
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You can keep a varnish longer if you wax it with real bee wax, no modern wax like the one for car, the real one only, several time a year. Very thin coat and very well buffed by hand, no machine. Little circle smooth motion.
Also wash your varnish often (lukewarm fresh water if possible)
You will be please of your long standing varnish.
Daniel
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  #12  
Old 08-05-2010, 04:50 PM
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alan white alan white is offline
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Quote:
Originally Posted by DennisRB View Post
How long do you have to wait between coats of varnish

A: to recoat without sanding?
B: to recoat with sanding?

Do I need to sand between each coat?

Thanks guys. Dennis.
Conditions are a variable so anyone who says 24 hours or else sand is not being too exacting. I'd play it safe and say within a few hours of the surface feeling dry you could recoat without sanding. I'd also say that multiple coats in rapid succession will produce a job that has to cure longer before being used so the advantage isn't speed but saving some sanding, though sanding is indispensible for achieving a flat surface. At some point in the later stages (maybe the fifth coat) one should sand anyway. Also, the next to last coat should be sanded.
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  #13  
Old 08-05-2010, 09:30 PM
Petros Petros is offline
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As Alen points out, if you want a smooth finish you will have to sand it between coats. I have found I can save time by brushing on the first 3 or 4 coats just when dry to the touch (depending on mix, about 8 hours), with no sanding. It bonds well but there are always little imperfections that build up with each coat, so the last 2 or 3 coats I sand smooth and than recoat. You usually have to wait longer between coats to sand it, 24 hours or more, on "traditional" oil finish you may have to wait as long as 5-6 days for it to be hard enough to sand (one reason I like the modern oil based finishes over the "traditional" finishes). You will want to go with 8 to 10 medium to thin coats if you want a durable finish. Thick coats will eventually crack, allow moisture in and peel a lot sooner than many thin coats.

I have found that most quality exterior grade oil based finish works great, I see no advantage to use the costly two part or special marine finishes. Today's mass produced products from the hardware store are pretty good and a bargain compared with the special marine finishes.

This makes for a great smooth finish. I think sanding between each coat is probably boarding on being fanatical about a finish on a tool such as a tiller that will get beat up and require touch-up and recoating regularly. It is normal, even with diligent cleaning and touch-ups 2 times+ a year, to have to strip and recoat it every 4 to 5 years if you want it to always look nice. I am not that picky on something used out in the weather, it might be different for a desk or other furniture used in a house or office. Although a smooth finish is attractive, if it is meant to be handled, a semi-loss or mat finish will be less slippery when wet. I have finished a lot of wood kayak paddles, and a less than perfect "shiny" finish is easier to hold.

Some people with wood boats carry a small container of finish with them at all times, and if they notice a nick or scratch they touch it up right than and there, while under way or at anchor, as they find them. Otherwise it is easy to forget to "take care of it later" and it shortens the life of the overall coating since moisture is allowed under the surface.
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  #14  
Old 08-05-2010, 10:54 PM
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DennisRB DennisRB is offline
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Thanks guys. I went with a marine exterior grade varnish. I just applied the first 50% thinned coat to let it soak in. Should I thin the rest of the coats a little too? By how much?
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  #15  
Old 08-06-2010, 02:53 AM
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waikikin waikikin is offline
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Dennis, only thin if you need to, maybe 5%, before you do some varnish thins when warmed up, just put the tin with the lid vented into some hot tap water, between coats a 3M scourer will be all you need to "de nub" particles, then tack down & recoat. Jeff
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