Primitive Archer

Main Discussion Area => Bows => Topic started by: upstatenybowyer on August 19, 2017, 08:31:54 pm

Title: Heat treating after an oil finish
Post by: upstatenybowyer on August 19, 2017, 08:31:54 pm
I have this HHB bow that's just about finished up and after a long round of shooting I notice the string alignment needs a little tweaking.

So I clamp it to my straightening caul and use my heat gun very briefly on one spot. I didn't think this would effect the tiller much cause it was just in one spot and only for a minute or two.

Low and behold that one spot bent a whole lot less, significantly effecting the tiller. I fixed the problem by going over the rest of the bow briefly with the heat gun.

All this got me thinking that the 6 coats of tung oil on the bow may have made for a much more dramatic effect from dry heat. The wood got much hotter with the oil finish and perhaps since I really took my time applying the tung oil, it had penetrated the wood deeply, causing a much deeper heat treating.

Anyone have any experience with this?
Title: Re: Heat treating after an oil finish
Post by: BowEd on August 19, 2017, 08:50:34 pm
I've noticed better heat treatment heat treating bows that as staves had their backs shellacked a couple of times.So much so that after a heat treatment the back will be stuck to the form melting the shellack to the form.Could be heat sneaking around to the back but not totally though IMHO.
I really think there is something to that.
Title: Re: Heat treating after an oil finish
Post by: PatM on August 19, 2017, 10:34:15 pm
Worth noting that bamboo flyrod makers tend to give their rod blanks a soaking and even pressure treating with an oil/varnish/sealer treatment which after curing stiffens the blank and reduces any tendency to set.

 I would think that a heat treated polymerizing oil will act similar to the way that the natural resins and oils in Osage shore up the cell walls and help give it its unique qualities.
Title: Re: Heat treating after an oil finish
Post by: JonW on August 20, 2017, 08:12:02 am
I use a lard/pitch mixture when heat tempering. I believe it helps.
Title: Re: Heat treating after an oil finish
Post by: Onebowonder on August 22, 2017, 09:23:26 am
I use a lard/pitch mixture when heat tempering. I believe it helps.
Got a recipe JonW? - OneBow
Title: Re: Heat treating after an oil finish
Post by: TimBo on August 22, 2017, 10:15:23 am
Just pitch some lard on it!
Title: Re: Heat treating after an oil finish
Post by: JonW on August 22, 2017, 11:10:22 am
No recipe Eric. Prolly 2 parts lard to 1 part pitch. I shoot for the consistency of paste shoe polish when melted and cooled off.
Title: Re: Heat treating after an oil finish
Post by: BowEd on August 22, 2017, 11:10:59 am
To me some resins would be beneficial.
Title: Re: Heat treating after an oil finish
Post by: PatM on August 22, 2017, 12:48:04 pm
To me some resins would be beneficial.

 That's the principle behind the flyrod blank treatment. The typical mixture is a penetrating marine sealer mixed with a resin based varnish perhaps thinned with a  solvent. The idea being to get the mix deep into the fibers and cells and then set and polymerize there as well.
Title: Re: Heat treating after an oil finish
Post by: BowEd on August 23, 2017, 07:50:05 am
Some sort of pitch mixture would also help make things more water proof also I would think.Also being acceptable of a finish.