Please Help ! Need Coating Old Wood Hat Blocks 1

[Block]

I need help with special wood finishing.

I have old and new hat wood-blocks that need good protection and that can withstand hot steam. Some of the old hat blocks are older than 100 years old and would like to refinish them.

A hat block (form, mold) is used to shape/form hats into different styles. A hat-body (a shapeless hat made of felt or straw) is pulled down over the hat wood-block, then steamed and let to dry to take the shape of the wood-block.

What I need is some type of coating to protect and beautify the hat wood-blocks.

To test things out, so far what I've used on scrap wood is the following:

Minwax Helmsman Spar Urethane and Minwax Clear Shield and have not been successful.

I have let both of these products dry on the scrap wood for 48 hours and then apply steam as if I was blocking a hat, but they jello out (gets mushy) and rub off onto the hat material.

Is Urethane the way to go?
Am I using the right brand?
Should I let them dry for a longer time?
Should I used a totally different coating all together?
Should I use some type of Epoxy instead?
If it matters, I'm also staining the wood before the Urethanes are applied.

I think maybe epoxy may work because my 12 year old son has a Slammer Skim Tuff skim-board that needs to be waxed before it is used. Before it is put away, the wax has to be removed and guess what I use to remove the wax? Yes, the same steam that I use for building the hats. Nothing happens to the board at all it just gets clean and it looks beautiful. I think this skim-board company uses epoxy to toughen and beautify the thin wood skim-board. What do you think?

What kind of epoxy do you think I should use and where do I get it? Keep in mind that the epoxy needs to be brushed on or sprayed on and has to finish smooth as glass.


Thank you and any help will be appreciated!

 

[berkshire]

Block (Materials)
I would suggest a two part marine grade poly urethane or epoxy varnish.
I would also suggest you coat the entire felting block so that the wood cannot pick up moisture through the base.
If you do not the wood will expand and contract through moisture changes and crack the varnish.
B.E.

 

[Block]

Thank you berkshire:

I will give that a try and see how that goes. Though, I'm not really having a problem with the moisture part of it. The poly urethane I'm using does not hold up to the heat of the steam.

I basically steam the hat for about 15 to 20 seconds in one large part of the hat which is on the block before I go to the next part, for example, the top of the hat.

There is another way to block/shape hats and that is to steam the hat body off the block and then quickly slip it over the block, but this method does not give you the best results.

Again thank you.

 

[rhodie]

How about boiled linseed oil?

 

[btrueblood]

The epoxy finishes are the way to go, just about any epoxy will work okay. Polyurethane and steam (or even just hot water) don't mix, as you have learned, the urethane breaks down due to hydrolysis.

 

[Block]

Yes, I have thought of oils, but I didn't know which one to use. I will try it and see how that works. My only fear is that it may leave to much residue on the hats.

I like the idea of oils and natural things as I'm concerned of the vapors going up my nose when steaming the hats.

Thank you rhodie.

I'm also looking into:

Silmar 249 Clear Polyester Surfboard Resin

700 Vinyl Ester Resin

http://www.uscomposites.com/polyesters.html

What do you think?

 

[btrueblood]

I wouldn't use polyester, either - it too will break down under exposure to steam.

And as for linseed oil - exposure to steam for long periods may soften the finish. Also, it's not very durable to abrasion, and it supports mildew growth unless treated with a biocide.

 

[tomwalz]

Did you ever try a wood or furniture discussion group?

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

 

[Block]

Thank you, I will try that.

 

[epoxybot]

Block, I can't recommend that you use any coating that represents a moisture barrier. Wood is a breathing expansive material. Many of the coating materials will have high flash point, unbound solvents, diluents or plastizers that will not responds well to steam.

I foresee the possibility of these materials, shrinking and crazing, delaminating or getting cloudy.

Wood needs some humidity unless it has been specially dried.
Baking the coating at a temperature higher than the steam would be helpful or not. The wood could lose requiste moisture and crack. The coating could be too thick and crack.

What is a deal breaker is that hat blocks get stuck with pins which will compromise these sealer/coatings during the steaming.

Wooden cutting boards last if you occcasionally apply usp grade mineral oil. Thompsons Waterseal (Siloxane) also might be worth a try.

 

[bigbadbaz]

What did you use in the end to coat the blocks? My wife has just bought a couple from Ebay which require recoating, Any help would be much appreciated.