Doug Fir is a bit stiffer than Ash, but Ash can bend further than Fir without breaking. I use both when restoring or building horsedrawn sleighs. They both have their place. I'd stick with Fir if it was me.
Polyfiber's Epoxy varnish is the most awesome wood finish I've ever found. I've got a chunk that I let dry in the bottom of a mixing cup in the 80's, and it's my "demonstrator". You can still put a mark in it, using your fingernail, without it cracking today. That is what you're looking for. Many wood finishes are brittle, and as you can imagine, will crack when something smacks them. The resultant crack can let in the elements to the wood, which is what you don't want. A stringer isn't going to see much wear and tear, but it could receive a little blow somewhere in it's life, especially from the outside. Their epoxy varnish also penetrates extremely well, when applied per the instructions and thinned a bit extra on the first coat. I also make sure the wood is very dry and warm....seems to help suck the varnish right in.
John

hardtailjohn wrote:Doug Fir is a bit stiffer than Ash, but Ash can bend further than Fir without breaking. I use both when restoring or building horsedrawn sleighs. They both have their place. I'd stick with Fir if it was me.
Polyfiber's Epoxy varnish is the most awesome wood finish I've ever found. I've got a chunk that I let dry in the bottom of a mixing cup in the 80's, and it's my "demonstrator". You can still put a mark in it, using your fingernail, without it cracking today. That is what you're looking for. Many wood finishes are brittle, and as you can imagine, will crack when something smacks them. The resultant crack can let in the elements to the wood, which is what you don't want. A stringer isn't going to see much wear and tear, but it could receive a little blow somewhere in it's life, especially from the outside. Their epoxy varnish also penetrates extremely well, when applied per the instructions and thinned a bit extra on the first coat. I also make sure the wood is very dry and warm....seems to help suck the varnish right in.
John

Great info! Thanks John.

We used aluminum stringers on our Bearhawk, purchased from Aircraft Spruce. Yes we had to splice them, wasn't a big deal honestly to do it. Either would work, we tried to keep the spruce parts down on our build - we mostly succeeded.