Osage and Dry heat? Revisited

[Pat B]

I never use oil to prevent checking, it won't. That's what the shellac on the back is for and it has for me.

[bjrogg]

I never use oil to prevent checking, it won't. That's what the shellac on the back is for and it has for me.

I haven’t either Pat. I always thought it was to keep the scorch marks from happening.

I don’t know for positive if it does anything to cure checking on back seeing I’ve never tried it before, but I don’t understand how it would applied to belly if it does. I have used oil on back when I didn’t have anything else to seal a freshly chased ring.

Bjrogg

[Eric Krewson]

I need to retract my statement that I never get checking on dry heat corrections and change it to very seldom get checking.

I went out to the shop yesterday to work on a bow that I had trouble with belly cracking when I tried to bend in the recurves and there it was; a little 1" check on the back where I made the most extreme bend. I tried the bend twice and got belly splintering both times. I went out to the shop to file off the splintered wood and glue an underlay on to build the wood back up.

It was then that I thought back and remembered a few staves over the years that did indeed get a small check or two, I remembered that I kept a tube of superglue close at hand on these staves and instantly put a puddle of superglue over any crack that started to form no matter how small.

Sorry for mis-information, at 75 these senior moments come around more and more often for me.

[bentstick54]

I’m only 68 but starting to understand about those senior moments Eric. That’s how I have treated the checks also, by saturating them with thin super glue before finishing.

[Eric Krewson]

I hit them up with superglue while the wood is still hot from correcting, the glue seems to penetrate better hot and stops small checks in their tracks so they never get bigger.

[bradsmith2010]

I had some very old osage gifted to me from fence post,, 50 years old had been laying on the ground,,
I tried working to a ring, and a check came up,, I would go to next ring and the check would open again,, till I was running out of wood,, so put the super glue and just made the bow,,, but sometimes I think it may be the quality of the wood more than how we treat it, some wood maybe more prone to checking,, but just guessing,, so not so much the heating process causing it,, but the wood is just a bit different,,than another stave that might not check at all,, but who would think a 50 year old stave would start to check when you worked down to a ring,, I was surprised,,

[uwe]

Hi,
Just a quick reply without reading all comments: I used muskrat fat  with good results. If I want to put a layer of sinew, I use wood ash in water solution for degreasing.
I even experimnented with brake cleaner (quick and dirty (lazy), I know), but it works as well.
Cheers Uwe

[bentstick54]

You may be on to something Brad. I did two staves within days of each other with close to the same corrections needed to both. The one that checked which led to this thread, was cut 10 years ago, split, ends sealed and stored in my basement with bark on. The 2nd stave was 3 years old and treated the same way. I had no drying checks in the back of the newer stave.
For information purposes our house has central AC/ gas heat. Basement maintains 66 to 68 degrees year around with humidity running around 33% to 37% in winter and around 50% in the summer.

[George Tsoukalas]

If my meter (8-10 %) shows the osage stave is not dry, after chasing a heartwood ring, I automatically give it a coat of poly. Jawge

[bradsmith2010]

coat of poly is a great idea just in case

[Selfbowman]

You may be on to something Brad. I did two staves within days of each other with close to the same corrections needed to both. The one that checked which led to this thread, was cut 10 years ago, split, ends sealed and stored in my basement with bark on. The 2nd stave was 3 years old and treated the same way. I had no drying checks in the back of the newer stave.
For information purposes our house has central AC/ gas heat. Basement maintains 66 to 68 degrees year around with humidity running around 33% to 37% in winter and around 50% in the summer.

My staves are in the top of my bow shop getting to 120 or so in the summer. With a higher average humidity. Maybe it’s the heat more than the humidity.

[bentstick54]

Maybe Arvin. Like Brad said, without a moisture meter I’m just guessing. Going to see if I can pick one up later today so I can take some guess work out of it.

[bentstick54]

Ok, so yesterday I picked up a moisture meter yesterday, and could not get a reading on a roughed out bow that I had done after the last one that I had the drying checks develop on the back while making heat corrections. The moisture meter won’t register below 7%.
This stave was way worse than the last, so I took Pats advice and sealed the back with a coat of shellac, then I went ahead and used a little canola oil on the belly and grabbed the heat gun. I did the worst limb this morning and just took the clamps off. Pulled it over almost 2” sideways, and took the twist out at the same time.
Don’t no if it was the shellac, or the canola oil, or combination of the two, or none of the above. But it did not check, and I believe the oil may have helped pull the heat into the wood deeper quicker so it didn’t scorch the belly. The wood seemed to reach the bending point faster and easier.
I hope to do the other limb tomorrow, and will see how it goes.

[TimBo]

Looking good - you really moved it a lot!  I have a few of those sideways staves, and whenever I see them my inclination is usually to keep looking for a straighter one...

[Will B]

Looks really good Bentstick. I have done exactly what Pat recommends with very good results on straightening Osage. Good luck with your other limb. Hope you get a nice bow out that stave.