: That's the difficulty with not knowing how a material is supposed to handle.
: My first boats were varnished with a Benjamin Moore spar varnish that
: seemed to be fine (to my relative inexperience with varnishes at the time)
: but I'd always have gummed up sandpaper whenever I'd try to apply a new
: coat. Even years later!

: When I finally switched brands after talking to the epoxy maker I could see
: the difference immediately. Sanding a dried/cured coat made dust instead
: of gum.

: All the best,

: Rob Macks
: Laughing Loon CC&K
: www.LaughingLoon.com

I asked Daren Newfeld in an e-mail about his experiences using Helmsman's Spar Urethane and I have been reading this great book by Bob Flexner (UNDERSTANDING WOOD FINISHES) and here is what I have come up with. Below is my e-mail to Daren.

Hi Daren,

Boy, thanks for your answers about using Helmsman Urethane and how you apply it. You are right about the manufactures not knowing their own products. I had an e-mail from the Minwax tech answer man this morning saying that he never had any experience with Helmsman Urethane Varnish, while an earlier e-mail from him to me said not to use it on boats. Below, I pasted his latest answer to me.

"John : I have no experience with the urethane you speak of. It will probably bond well enough with a fully cured and preped epoxy. The only thing is urethanes tend to be brittle and don't seem to last well on exterior boat surfaces."

In my experience using polyurethane on my sailboat mast which flexed a great deal all of the time while sailing I never saw any sign of it being brittle over a 10 year period.

In Bob Flexner's wonderful book "Understanding Wood Finishes" he has different finishes rated in different categories from 1 to 5, 5 being the best. Polyurethane's have more 5's then anyother finish, including the two other types of varnish. WATER RESISTANCE--5, WATER VAPOR RESISTANCE--5, WEAR RESISTANCE--5, SOLVENT & CHEMICAL RESISTANCE--5, APPLICATION EASE BRUSH OR CLOTH--5. ALSO, POLYURETHANE IS RATED AS THE MOST SCRATCH RESISTANT OF THE THREE MAJOR VARNISHES, WHICH INCLUDES ALKYD & PHENOLIC VARNISHES. Clarity is rated--3, where Alkyd Varnish & Phenolic Varnishes are rated--5. The big knock against polyurethane is that it doesn't bond well even with itself and therefore a sanded mechanical bond is recommended. But Daren, I think you have dispelled that by using urethane on your three boats without problems.

I have an e-mail out to Raka (I use their epoxy) asking if Helmsman Urethane is compatible with their epoxy and I will also test it out first before I put it on my boat.

Again thanks for your help and I will keep you updated on my project.

Take care,
John