Polyurethane

[DC]

I was just reading this article on arrow matching
 http://savagearcher.com/wp-content/uploads/2013/02/Arrow-Workshop.pdf
 And he says this
" Use “Interior Grade Polyurethane” since this seals completely, exterior grade is permeable
to water vapour."
I have never heard this before although it kind of makes sense. Can anyone confirm/refute this?

[Pat B]

I always used water based poly for arrows when I dipped them. Never had a problem with it.

[crooketarrow]

  I use to use poly on arrows but for the last 10,12 years I've used bee's wax on all self arrows and bows.

[basilisk120]

I think he is over thinking that. 
He talks about using the interior Poly because its is impermeable then goes about thinning it with mineral spirits which would make it slightly permeable.  As the spirits evaporate they will leave microscopic openings were the gas escaped from.  Danish oil is also not 100% impermeable when it dries. 

The purpose of most finishes is not to prevent any water from entering or leaving the wood but to slow it down.  Unless your going from a rainforest to a desert regularly I think that worrying about a slight gas exchange with the environment is negligible.   


One last thing.  Danish oil is a soft finish that will scratch a wear quickly, poly is more protective but from experience I know that it too will quickly show "target rash" and wear through. So unless you are re-applying the finish, wear and tear will negate the impermeability of any finish. 
 

[DC]

I'm using an acrylic polyurethane called "Stays Clear". It's made for floors so it's hard. I've used it on my R/C racing sailboats which get tough banging and scraping. At re-finishing time it's hard to sand so it's tough stuff. The only downside it that it's shiny which is a no-no for hunters. I just target shoot so it doesn't matter to me.

[bow101]

I'm using an acrylic polyurethane called "Stays Clear". It's made for floors so it's hard. I've used it on my R/C racing sailboats which get tough banging and scraping. At re-finishing time it's hard to sand so it's tough stuff. The only downside it that it's shiny which is a no-no for hunters. I just target shoot so it doesn't matter to me.

I'm using Exterior water based Poly on everything; this is not good.?

[DC]

That's what I'm trying to find out after reading the article. Looks like the consensus is it doesn't matter.

[Puha Ekapi]

I've used the waterborne polys for a number of years and they work very well. I thin them with about 20% distilled water and use a dip tube. Most are too thick out of the can for good dipping results. They dry quickly to handle, no fumes so you can even do it in your house. Full cure does require a day to several depending upon the specific formulation you are using. I have not had any issues whatsoever with with moisture...in practical terms they protect as well as any finish I have used. The one I am currently using is em9300. It's very, very tough and crystal clear.