Polyurethane Clear coat on wood

Here’s a pic of Endura polyurethane brand clear coat on wood (steering wheel )
Imron is another brand

That is one odd-looking steering wheel!

:grimacing:

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Hmmm – at first blush, I thought it was a propeller
Craig

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Is this another British and American language test? :joy:

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I always used Marine Spar Varnish on my 3.8 MK2 dash with great results.

I’m using marine Interlux Perfection Plus on the external teak on the boat. It’s a two-part urethane that cures crystal clear and very hard…similar to Imron as I understand it. It’s currently abut $95/quart plus tax via Amazon. Also would need the appropriate thinner for either brush/roller…or spray on. I’d spray it on a steering wheel…figure four or five coats.

The important thing with finishing wood is to make sure that the finish has some flexibility. The wood can move with temperature and humidity, you don’t want something to brittle that will crack and may flake off. I’ve been known to use a urethane clearcoat with a little flexible additive.

Most polyurethanes, at least automotive formulations, have some flexibility. Many years ago in a scrapyard I was looking at the hood of a 280Z painted in Imron and I peeled some of the paint where the impact cracked it. It was not at all brittle. (remember that many flexible bumpers are urethane.)

I pour excess mixed Imron clearcoat into a old margarine tub. When it cures, it is not a rock-hard mass like fiberglass resin. You can feel it has some give to it. The application instructions for the Imron I have say that flexible additive is not needed for painting flexible plastic parts.

Dave

I used Sikken Cetol on my boat teak never ending battle

Yes it’s a prop
I figured all the professors would chime in you guys are so predictable :smile:
It was intended as an example of what wood looks like with clear coat
Do your steering wheel while painting the car in base clear, you’ll save a few steps …:thinking:but what do I know
I love you guys

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Imron is a quite hard type of paint with very little flexibility.
If what your using is similar to Imron, i would stay away from it.

I disagree. Imron in most of its forms is a relatively flexible paint - almost rubbery in some ways. Of course there probably is a Imron variant that may be brittle-hard but I haven’t seen one yet.

This goes from Imron jobs from the late 70’s-early 80’s to the stuff I use now purchased in the early 2010 era. And there are many polyurethane varnishes sold for woodworking.

It’s probably a great application for a propeller because it would resist chipping and abrasion from dust and bug/creature strikes, yet can accommodate the flexing of the propellor itself under load (more common with a metal propellor admittedly.)

It’s also why polyurethanes are commonly if not exclusively used on airplanes - in addition to chemical and abrasion resistance, metal plane structures flex in flight. Stressed skin structures flex and balloon under stress. Wings bend up and down.

Take a look at a B-52 bomber. Note how wrinkly the skin is. And note how they have outrigger wheels on the wingtips that don’t touch the ground. They don’t touch when the plane is empty. They do when it’s fully loaded.

Dave

Hopefully it wasn’t you who did this safety wire job…

safety wire propbolts_safetywire_3

Left handed?

The problem I’ve often had with varnishes, including polyurethane, is more one of adhesion to the wood than flexibility. It’s particularly the case in items exposed to strong sunlight. It could be overcome with some by making the first coat 90% thinners and progressively increasing the varnish to thinner ratio in the subsequent layers.

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I stripped what little varnish that was left and used a wipe on polyurethane. i have 4-5 thin coats and with a scuff and a few days drying time i add more coats.

No that’s not me …at least he tried
How many mistakes do you folks see …a good learning event

Half of each pair looks okay to me (the non aviation non expert). But I’m thinking you really need all of the bolts to stay tight on a propeller.

NONE of those would pass an A&E’s eagle eye!

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I ve used pretty much everything over the years on various boats including cetol, Bristol, varnish, epoxy with clear Awlgrip etc.

The best which I ve now been using for the last 5 years is Awlwood by Awlgrip. 1 coat of primer, 7 coats of clear and good for a year in the Florida sun. Works great for interior trim etc.

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Hummmm, Wrong Bolts just to start with! Grade 5? Not MilSpec or AN Prop Bolt spec’d. As Paul cited "Won’t pass an Eagle eye A&P’s (not A&E) inspection. Last - ends are not turned back. As pictured the ends can slice and dice skin nicely!!!

Happy Trails,

Dick