how late would you say is to late for steam

[DVSHUNTER]

I was just wondering how long after a tree is cut and split would you say that is would be best to not steam and switch to dry heat.  I have a stave that I cut split and worked down to a ring sealed with shellac that is about four months down.  I would like to steam it and was wondering if I should or if I should just let it dry more and use the heat gun.

[Pat B]

If you seal the area to be steamed with shellac it will prevent the moisture from entering the wood. The shellac can take the heat and moisture.
   If you took the stave down to almost bow size after you felled the tree it should be dry enough for dry heat if that is the way you want to go.

[DVSHUNTER]

Pat, do you think that I would harm the wood if I used steam?  What negatives are there to steaming dry wood?

[Pat B]

The problem is you are introducing moisture into the wood and as it dries back out it is subject to checking(drying cracks). If you seal the area to be steamed with shellac(primarily the back and ends) it will prevent the moisture from entering the dry wood. It is the heat that causes the wood to bend. The steam is the carrier for the heat.
  What kind of wood do you have? Some woods prefer one method(wet or dry) over another. Osage bends very well with dry heat but hickory prefers steam.

[DVSHUNTER]

I am bending a nice osage stave.  I always use the steam when I want to bend shortly after cutting.  In the past if I wanted to steam I would do so within a week or two of cutting the tree and splitting.  I have a few staves that were cut, split, chased, then sealed on the ends and back that were placed with the rest of my staves in a dry shed to slowly air dry.  That was four months ago. Now I want to make a bow out of one and wanted to know if I can steam it before I finish the drying process in my hot box, or should I just dry it out first and heat with the heat gun.  I just think that I get a hotter stave when I steam in my steam tube and was going to try a sharp curve in this bow.

[Pat B]

If the stave is relatively straight I would wait to bend it until you get it to floor tiller stage. At that point you have a lot less wood to heat and the bends are easier.
  The bow in the pics below was built 2 months after the tree was cut. The recurve bends were done with dry heat with no checking(ends and back sealed with shellac). I use a heat gun and oiled the wood well before heating and bending. I find I have better luck with dry heat than with steam plus I can continue to heat while on the form if necessary to complete the bend. With steam, once you are out of the steam tube you have only a minute or less the get the bending done.
  I haven't used steam since I started using a heat gun.
 
 

Many folks use steam to bend dry and wet wood with success. If you do use steam, seal the back and ends with shellac. Your wood is dry enough now it might check if it takes on moisture  and is dried again. Newly cut wood works well with steam and steaming it will actually help dry the wood some.

[DVSHUNTER]

Thanks for the help Pat.  Do you have any pics of the bending process that you used for that bow.  That looks great!  I am going to try one very similiar to that, but haven't finished my form yet.

[Pat B]

This isn't the same form I used for this bow but is the same idea.
 

[DVSHUNTER]

That looks very close to what I have drawn out for my newest caul.  I would say that My ends bend a bit more, but I am going for a recurve this time.  I just heated a stave tonight and after taking it off off my old caul there were very small checks in the back that were not there before heating.  This was the third time I heated this bow and the first time that I used oil when heating it.  These checks are very small and don't look to bad, but still I'm nervous.  I have heated other bows and haven't had this happen and was wondering if it has ever happened to anyone else before.

[Pat B]

If these cracks run with the grain(checks) then your wood was probably not dry enough. You can fill them with super glue and go on with what you were doing.

[DVSHUNTER]

Thanks pat.  Any idea as to why these showed after a third heating?  I store my staves in a hot bow kept at 90 when I'm not working on em and this stave spent four months in there worked down very close to floor tillered.  I think that is why it moved while it dried.