Painting hull

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Paul
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Joined: 20 Feb 2005, 21:26
Location: GBR

Painting hull

Post by Paul » 08 Apr 2005, 20:59

Ive just epoxied and glass clothed my timber hull and was wondering what type of paint to use for the finising touches? Would a final coat of epoxy resin over the paint be good?
Thanks for any advice
Paul :roll:
Paul spanner

Roy Thompson
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Post by Roy Thompson » 08 Apr 2005, 21:13

Can I ask a silly question. Why do you glass the wood outside? Is it for added resistance to damage? What wood are we talking about, balsa, cedar?
I have built a number of wooden hulls (Cedar and or Obechi) and they always come out lighter and just as stong and almost as resistent with 2 good coats of epoxy only without glass. The wooden hulls I have made with glass outside, even the same designs, have never seemed quite as beautiful, or fast....????
Roy Thompson
"WE DON'T SEE THINGS AS THEY ARE, WE SEE THINGS AS WE ARE" A.N.

Paul
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Joined: 20 Feb 2005, 21:26
Location: GBR

Post by Paul » 09 Apr 2005, 21:09

Hi
I love silly questions!
This is the first model boat of any description ive made.
Im following the method in Chris Jackson's book - Radio Controlled Racing Sailboats, so this is the only method i know!
Im using Lime by the way.
Paul spanner

Muzza
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Post by Muzza » 10 Apr 2005, 00:58

Paul

I'll assume your hull core material is balsa - in which case you really do need to glass the outside as it has insufficient impact resistance otherwise (IMHO).

On my boat, I applied two coats of epoxy undercoat, slightly thinned, by hand. I then wet sanded these right back until there was almost nothing left - but trying not to sand away any of the light fibreglass cloth. The purpose of this was to get a nice smooth and hard surface over the fibreglass, evening out the innevitable little bumbs and hollows. The more time you take over this, the better the ultimate finish.

Beyond that, further paint is cosmetic/aesthetic only. But because I don't like an ugly looking paint job, I finished it with the spray enamels you can pick up down at the hardware store. Choose one that you can sand with a fine grit wet and dry paper (but no finer than 600 grit - some people even say 400 grit is fine enough). You do not have to sand these finishing coats - but the general wisdom is that you will get a faster result. There are some good articles on the web explaining various peoples experiences and tips on finishing the paintjob.

Paint = weight, so be very mindful of this if you start to apply several coats.
Murray Buckman
USA 274

Roy Thompson
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Post by Roy Thompson » 10 Apr 2005, 19:18

I'll assume your hull core material is balsa
I think Paul says it's Lime (Tilia specias) which is very unusual but possible. It isn't anywhere as near as soft as balsa..but never having used it myself I don't know how resistant it would be to the bump and barge of an IOM fleet race.
In any case, as you say, painting is purely cosmetic and can easily pile on the grams of wt....
Roy Thompson
"WE DON'T SEE THINGS AS THEY ARE, WE SEE THINGS AS WE ARE" A.N.

cfwahl
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Post by cfwahl » 10 Apr 2005, 21:42

Lime is known here (US of God Bless America) as Basswood, other places as Linden, and is very common. Because it has virtually no visible pores, very little color variation or grain, and it is very uniform in density, it's favored for building architectural models and the like. Woodworkers in the age of hand tools preferred it for carving. As such, here you can buy it in any decent art supply store, in lots of stock sizes (sheet and strip; unfortunately for us, usu. in 36"/915 mm length only). It's not as strong as spruce, but much stronger than balsa, and certainly more durable. Density is about 2 to 5 times that of balsa, and just under that of spruce. Though it's technically a hardwood, it's a rather soft one.
Charles Wahl

Muzza
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Location: USA 274

Post by Muzza » 11 Apr 2005, 00:58

I didn't notice the reference to lime. I agree with the subsequent comments.
Murray Buckman
USA 274

Paul
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Joined: 20 Feb 2005, 21:26
Location: GBR

Post by Paul » 11 Apr 2005, 20:55

Thanks guys, ive learnt a lot already.
Its great to be able to ask so many experienced people.

For the record i am using Lime, simply because my local Model shop had a plentiful supply of the stuff! and being new to this game i didnt trust the strength of Balsa. I Know differently now.
Paul
Paul spanner

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