steam bending: pre-soaking?

[tacticalboxing]

I am about to wood bend a partially completed white oak bow and some have said that I need to put shellac on its backing to prevent checking.
If someone doesn't have shellac what else could be used? Would duct tape work? Also some have said to pre-soak the wood for 24 hours before using steam, would that prevent checking or would that still provide other advantages as well?
Should I do one or the other or both?
Please help good friends

[Pat B]

The thing about shellac is it can take the heat and moisture unlike most other products. You can buy a can of spray shellac for about $8 at your local hardware store.

[gfugal]

Tite bond 3 should work too if you have it. In testing the glue the did systematic tests where the boiled it several times, and the glue still held up. I'm going to experiment with Thompson's wood sealer but I don't have anything to report on it, I'm thinking it might work but I'm not sure.

[Pat B]

Thompson's water seal probably won't work. It hardly works well on a deck and the problem with TBIII, it might seal well but will be hard to remove if you want to. Shellac is carried with alcohol and can be removed with a rag wet with alcohol.

[gfugal]

Thompson's water seal probably won't work. It hardly works well on a deck and the problem with TBIII, it might seal well but will be hard to remove if you want to. Shellac is carried with alcohol and can be removed with a rag wet with alcohol.

Good reasonings. Thank you! I probably will try the Thompson's on a test piece still just cause it's so stinking cheap. Maybe it wears out with age, but if its fresh maybe it can hold up to the one time use of steaming? It won't hurt to try, but I won't get my hopes up.

[tacticalboxing]

So, does anyone think that pre-soaking would guard against checking?
Either way, what are the benefits of pre-soaking it in water for 24 hours before steaming?

[Pat B]

The stave will only check if it still has moisture in it. Checks are drying cracks. Soaking may aid in the bending but it is adding moisture to the stave to do so. The reason I like spray shellac(I keep a can on my work bench all the time) because it seals well with the moisture and heat but it is easily removed with denatured alcohol.
 I think Thompson's water seal is just linseed oil and alcohol or something similar.

[gfugal]

So, does anyone think that pre-soaking would guard against checking?
Either way, what are the benefits of pre-soaking it in water for 24 hours before steaming?

Yeah, I would say pre-soaking would increase the chance of checking because as I understand it checking is from water leaving the stave quickly. If you introduce more water it is more likely to leave quickly.

[DC]

How much are you bending it. Pre soaking is for fairly drastic bends. If you are just straightening a bit or flipping the tips I don't think it's necessary. I've never used White Oak but it seems to me it's on the top of the list of easy to bend woods, isn't it?

[gfugal]

If you are worried about bending it without breaking it, soaking might help, but using something like a metal strip to keep the fibers down might work better.

On the other hand if your more worried about checking then maybe drying it out with a hot box, or heat gun may help. But I would go with sealing the wood somehow like mentioned earlier.

[tacticalboxing]

yes, DC I have a chart that says that white oak is the  second best wood to steam bend. Well out of the ones on the list anyway.

[tacticalboxing]

I am trying to straighten it but also put some reflex and deflex in it. This is my first time so I was just trying to hedge my bets by pre soaking if it would increase my chances of success. But I trust you guys so if you all think its not necessary I won't do so.

[simson]

I have never presoaked any wood for bending, I also don't use shellac for this procedure.
Like Pat said, checking is the answer when the stave is still wet, or when you steam too long..
Work down to near dimensions, then make the bend with about 20-30 min in the steamer (belongs to wood thickness)

[tacticalboxing]

ty simson for your input
so I will not  be pre soaking it, 
but one question: you say to only steam it for about 20-30 minutes, is that typical for a bow?
I have heard 45 minutes from most and a few said about an hour.
Does it depend on the type of wood and whether it is green or seasoned?

[DC]

General rule is one hour per inch of wood. Green wood a little less. Most of the time we're bending wood about 1/2" thick so that is the half hour. Google "the Veritas steaming booklet" but remember that most of our bends are quite mild and the strap isn't necessary. It is with sharp, small radius recurves. Practicing with off cuts and scraps is never a bad idea.