Primitive Archer

Main Discussion Area => Bows => Topic started by: NeolithicMan on December 10, 2013, 11:36:28 am

Title: Waiting after tempering, how long?
Post by: NeolithicMan on December 10, 2013, 11:36:28 am
 I know its been posted before by a few people, but I would like to get more peoples opinion.

After a good heat tempering of the belly, how long before you take the bow out of the reflexed position? whether it be a form or strung backwards with a piece of wood raising the string. Relative humidity is the main factor for leaving it in position, after cooling of course, but are there any other factors in play?

At the moment I am working a shagbark hickory recurve, but any info on any wood in this regard would be appreciated.
Title: Re: Waiting after tempering, how long?
Post by: Pappy on December 10, 2013, 11:40:43 am
I usually just leave them on the form until they are good and cool,sometimes over night,but after that I give them several days/ 3 or 4 at least before I start bending them again. :)
Pappy
Title: Re: Waiting after tempering, how long?
Post by: NeolithicMan on December 10, 2013, 11:47:54 am
Dang... I hate waiting. Especially after working like a mad man for hours in a row then it all just stops. good thing I have more bows started!
Title: Re: Waiting after tempering, how long?
Post by: Pat B on December 10, 2013, 11:54:40 am
I'm with Pappy. I let tempered bows stay on the form over night then give them 3 or 4 days to rehydrate before stressing them. It pays to have 2 or 3 bows going at once to prevent impatience from calling in Murphy's law.  ;)
Title: Re: Waiting after tempering, how long?
Post by: Carson (CMB) on December 10, 2013, 01:19:48 pm
It might not be necessary, but if it is a piece of whitewood, and I temper it pretty thoroughly, then I let it rest for 2-3 weeks.   This results in lots of bows in the works at any given time.   :)
I think 3-4 days is plenty for osage.  It likes heat!
Title: Re: Waiting after tempering, how long?
Post by: PEARL DRUMS on December 10, 2013, 01:25:40 pm
I'll just plead the 5th on this one..;)
Title: Re: Waiting after tempering, how long?
Post by: Pat B on December 10, 2013, 01:26:55 pm
You just incriminated yourself by saying that Pearlie!  ;D
Title: Re: Waiting after tempering, how long?
Post by: PEARL DRUMS on December 10, 2013, 01:28:16 pm
Perhaps!
Title: Re: Waiting after tempering, how long?
Post by: Onebowonder on December 10, 2013, 01:31:35 pm
It may just be that I'm ignorant of what better results I might have with more patience, ...but I've always just figured cool to touch was kewl to work on and kuul to remove from the caul.  Maybe I drank too much koolaide... 

If the metered MC is back to what it was prior to tempering, is more moisture change still going on?

OneBow
Title: Re: Waiting after tempering, how long?
Post by: PEARL DRUMS on December 10, 2013, 01:37:16 pm
After a simple heat and move scenario, Im sure cool to the touch is fine. But a full blown temper may warrant a bit more wait time than just cool to the touch.
Title: Re: Waiting after tempering, how long?
Post by: Pat B on December 10, 2013, 01:41:15 pm
I even give my heat to bend/straighten over night to insure that the internal temp of the wood is cool too. The surface temp might feel cool but internally it could still be hot(warm).
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 01:49:43 pm
Can't count how many times I've yanked em(various woods used) off a form an hour later or less and immediately went to finish tillering n shooting etc....n I've seen plenty of yins others guys(won't say names cough cough) do the same with no I'll results....  >:D ....heck its hickory....once its cool take it off the form and start bending that beech  >:D
Title: Re: Waiting after tempering, how long?
Post by: Onebowonder on December 10, 2013, 01:49:51 pm
NeoLithicDude - Please listen to these guys with years of experience and NOT me.  It would be little surprize that I need to be more patient in all things bowering.

OneBow
Title: Re: Waiting after tempering, how long?
Post by: NeolithicMan on December 10, 2013, 02:04:18 pm
This is the bow I am working on now. I treated it yesterday morning and I was planning on leaving it like this for another day but now I am thinking a day or two on top of that from your guys' advise.
Is there benefit from removing the string and dowel? I had figured leaving it would not hurt if not help the bow... now that I have typed it I realize I have no evidence or reason to think that
Title: Re: Waiting after tempering, how long?
Post by: Don Case on December 10, 2013, 02:07:13 pm
When you're waiting for a bow like this to re-hydrate, would it be counter productive to give it a little spritz of water?
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 02:19:45 pm
I'm just gonna say it and defend my stance because me and plenty others have proven this time n time again hundreds of times....as long as your wood isn't already at 6% and you don't blacken it you should be more than aok to take it off the form after its cooled and start working on it again....and john your just north of me and pretty much have the same climate conditions as me...you should be fine to start working it now...so either take that dowel and string off(cus leaving it ain't gonna do anymore good)or leave it on and throw some sinew on that  >:D
Title: Re: Waiting after tempering, how long?
Post by: Del the cat on December 10, 2013, 02:20:05 pm
I took an old Hickory English longbow with a load of set and heat treated it to slight reflex just to see what would happen. Got to work on it re-tillering it the next day no prob'.
http://bowyersdiary.blogspot.co.uk/2013/03/big-bow-detail-and-hickory-challenge.html (http://bowyersdiary.blogspot.co.uk/2013/03/big-bow-detail-and-hickory-challenge.html)
But for preference I'd give it a couple of days if it was a precious stave... ah precioussssss
Del
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 02:39:44 pm
Its as simple as this folks.....know the moisture content of your wood...as bowyers we should know the mc of a stave before bending it...so if you know(which you should anyways)then you'll know if you need to wait or not......I weigh all my staves/bows before and after I temper them....the most weight I've lost and the average is only losing a tenth of an ounce(n sometimes nothing)....I know that's not even a half percentage point...so as long as your wood is already above safe levels and in the safe zone your more than fine to start bending it again asap off the form once cooled(which usually takes an hour on average)
Title: Re: Waiting after tempering, how long?
Post by: NeolithicMan on December 10, 2013, 03:44:37 pm
I dont know MC or weight of my bows, because I do not own a meter or a scale. I dont even usually measure them with a tape measure until done. I like rough measurements with a string and my fingers best. I dont think its bad to use these things I am just not as concerned with exact measurements or pushing every last once I can out of the wood. Eventually I may buy more things and be meticulous about all the details but for now I like the "wing it" approach. I know some of you guys are cringing thinking about some kid swinging a hatchet at almost random pencil lines drawn quickly on a half seasoned stave until a bow looking chunk falls out of it but thats what has worked so far and my broke @$$ is to cheap to put more than elbow grease into archery right now. maybe this x-mas season Ill get lucky from a family member! 
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 04:32:58 pm
You dont need a moisture meter(there useless IMO) in bow building to know the mc of your staves,or a scale to weigh them...all you need to know is the temperature and relative humidity in where your wood stored...and that only will cost you 5-10$ to know,and something you should have where you store your wood regardless of how simple and cheap of a bow builder you wanna be...you really need to know the Mc of your wood for many reasons. <------- that's a big period
Title: Re: Waiting after tempering, how long?
Post by: artcher1 on December 10, 2013, 04:44:14 pm
Can't count how many times I've yanked em(various woods used) off a form an hour later or less and immediately went to finish tillering n shooting etc....n I've seen plenty of yins others guys(won't say names cough cough) do the same with no I'll results....  >:D ....heck its hickory....once its cool take it off the form and start bending that beech  >:D

I'm just gonna say it and defend my stance because me and plenty others have proven this time n time again hundreds of times....as long as your wood isn't already at 6% and you don't blacken it you should be more than aok to take it off the form after its cooled and start working on it again....and john your just north of me and pretty much have the same climate conditions as me...you should be fine to start working it now...so either take that dowel and string off(cus leaving it ain't gonna do anymore good)or leave it on and throw some sinew on that  >:D

Its as simple as this folks.....know the moisture content of your wood...as bowyers we should know the mc of a stave before bending it...so if you know(which you should anyways)then you'll know if you need to wait or not......I weigh all my staves/bows before and after I temper them....the most weight I've lost and the average is only losing a tenth of an ounce(n sometimes nothing)....I know that's not even a half percentage point...so as long as your wood is already above safe levels and in the safe zone your more than fine to start bending it again asap off the form once cooled(which usually takes an hour on average)

You dont need a moisture meter(there useless IMO) in bow building to know the mc of your staves,or a scale to weigh them...all you need to know is the temperature and relative humidity in where your wood stored...and that only will cost you 5-10$ to know,and something you should have where you store your wood regardless of how simple and cheap of a bow builder you wanna be...you really need to know the Mc of your wood for many reasons. <------- that's a big period


Do you feel like your talking to the hand Chris. ;D ;D ;D ;D


Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 05:00:49 pm
Yes I do Art....or maybe a wall  :laugh:
Title: Re: Waiting after tempering, how long?
Post by: Gordon on December 10, 2013, 05:51:03 pm
When I temper a belly, I let the bow sit overnight and resume tillering as early as the next morning. I've never had one blow on me yet.
Title: Re: Waiting after tempering, how long?
Post by: Marc St Louis on December 10, 2013, 05:52:12 pm
Can't count how many times I've yanked em(various woods used) off a form an hour later or less and immediately went to finish tillering n shooting etc....n I've seen plenty of yins others guys(won't say names cough cough) do the same with no I'll results....  >:D ....heck its hickory....once its cool take it off the form and start bending that beech  >:D

I popped a back ring on the first Elm I ever heat-treated when I started this whole heat-treating thing back in the early 2000's by doing just that.  Now I wait
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 06:07:20 pm
Can't count how many times I've yanked em(various woods used) off a form an hour later or less and immediately went to finish tillering n shooting etc....n I've seen plenty of yins others guys(won't say names cough cough) do the same with no I'll results....  >:D ....heck its hickory....once its cool take it off the form and start bending that beech  >:D

I popped a back ring on the first Elm I ever heat-treated when I started this whole heat-treating thing back in the early 2000's by doing just that.  Now I wait

What was the mc of the wood before you tempered it? Did you weigh it before and after? Did you blacken the belly? Was it over cooked and caused the back to become brittle? Heck Marc..it was your first time...it could have been other reasons than blaming mc loss... I've just seen way too many bows made with wood at 8-10% mc tempered and finish tilllered before it was 24 hours from being tempered....like I said I weigh all mine before and after tempering and a tenth of an ounce lost at the most means very little actual mc drops in the wood...the numbers don't lie(to me at least)




Title: Re: Waiting after tempering, how long?
Post by: IdahoMatt on December 10, 2013, 06:16:00 pm
How do you really feel Hawkster? >:D
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 06:20:24 pm
Just discussing my fact based findings matt in a friendly way with my fellow brethren  ;)
Title: Re: Waiting after tempering, how long?
Post by: DarkSoul on December 10, 2013, 07:19:26 pm
I've once measured a 75% moisture regain after about 16 hours of waiting (basically overnight). I therefore recommend two days.
Title: Re: Waiting after tempering, how long?
Post by: Marc St Louis on December 10, 2013, 08:53:24 pm
Can't count how many times I've yanked em(various woods used) off a form an hour later or less and immediately went to finish tillering n shooting etc....n I've seen plenty of yins others guys(won't say names cough cough) do the same with no I'll results....  >:D ....heck its hickory....once its cool take it off the form and start bending that beech  >:D

I popped a back ring on the first Elm I ever heat-treated when I started this whole heat-treating thing back in the early 2000's by doing just that.  Now I wait


What was the mc of the wood before you tempered it? Did you weigh it before and after? Did you blacken the belly? Was it over cooked and caused the back to become brittle? Heck Marc..it was your first time...it could have been other reasons than blaming mc loss... I've just seen way too many bows made with wood at 8-10% mc tempered and finish tilllered before it was 24 hours from being tempered....like I said I weigh all mine before and after tempering and a tenth of an ounce lost at the most means very little actual mc drops in the wood...the numbers don't lie(to me at least)


I think it was a year or 2 after I wrote that first article one of the members, I believe it was Lennie (Tom Sawyer), did some tests on moisture loss after tempering.  His tests indicated that the actual amount of moisture lost from the process was miniscule and not worth considering, he was using seasoned, dry wood but I don't remember which type.  The bulk of the moisture loss is on the outer surfaces.  Back then I didn't measure the MC of wood, still don't, I just monitor(ed) the RH of my environment. 

Overcooked??? Really???  Could have been, might have been....naah I don't think so.  The Elm was high quality Elm with decent growth rings plus I had no trouble with the other staves from the same tree.  I'm not saying that you will pop a back ring every time but all it takes is once to ruin your day.
Title: Re: Waiting after tempering, how long?
Post by: Don Case on December 10, 2013, 08:58:36 pm
 You popped a back ring from cooking the belly?  Am I missing something? How does that happen?
Don
Title: Re: Waiting after tempering, how long?
Post by: Marc St Louis on December 10, 2013, 09:15:33 pm
Don
By trying to tiller the bow too soon after tempering.  Hot wood dries out fast and when you temper a bow the back gets hot = dry.  The outer surface of the wood is where it is the driest and dry wood becomes brittle in tension hence a tension failure.
Title: Re: Waiting after tempering, how long?
Post by: Don Case on December 10, 2013, 09:48:40 pm
Were you tempering the belly or the back or both? All I've heard of is tempering the belly and I didn't think that would affect the back.
Thanks
Don
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 10, 2013, 09:54:01 pm
Cool Marc...good to know my findings are the same as lennies ...and I don't blame ya for waiting now...if that happened to me I'd wait too ;) all it takes is once......I must be on one loooooong  lucky streak  :laugh:

@Don....just the belly...but when tempering proper the heat will penetrate so far the back will actually be too hot to touch
Title: Re: Waiting after tempering, how long?
Post by: NeolithicMan on December 10, 2013, 10:44:49 pm
So I think that the next bow I am going to try Bhawks method. If it works for me I will let ya know. This one is for someone and I would rather play it safe and wait even if it doesnt matter (good trade). Next one will be a little more simple too.
Title: Re: Waiting after tempering, how long?
Post by: blackhawk on December 11, 2013, 07:28:30 am
I wouldn't quite call it my method,and how I've handled every bow I've made....I've just personally seen firsthand others and myself start bending them the same day they were tempered or before 24 hours of tempering them with great success and no issues in doing so...
Title: Re: Waiting after tempering, how long?
Post by: PEARL DRUMS on December 11, 2013, 07:45:07 am
The only reason I wait anymore than a half day is because Im busy with other stuff. Ive never had one break or crack. I don't weigh them either, don't even have a scale to do that. I use dry wood, not sure of the MC as I don't calculate that either. My approach has ZERO to do with proving anybody or any theory wrong, I have no patience and ADD hits hard in the shop.
Title: Re: Waiting after tempering, how long?
Post by: dwardo on December 11, 2013, 08:10:29 am
Usually a minimum of 24 hours. Mostly my coincidence as I do most of my bowing at night when the littlun is asleep. By the time its cooled down I will probably be in bed and then its another days before I get chance to work on it again.
Also the RH here works in my favour, currently about 81% outside, about the norm for most of the year.
Title: Re: Waiting after tempering, how long?
Post by: Pappy on December 11, 2013, 08:25:36 am
Good info,but I will just wait,no big deal ,got plenty of other stuff to do,and like you said Chris it just takes one to make you say,man maybe if I had just waited. :)
Back to the question,I guess you can go for it or just wait,  :-\ ??? I don't know. ;) :)  I do know one thing waiting for sure ant going to hurt anything,thats why I wait.  ;) 
 Pappy
Title: Re: Waiting after tempering, how long?
Post by: Del the cat on December 11, 2013, 09:28:27 am
Don
By trying to tiller the bow too soon after tempering.  Hot wood dries out fast and when you temper a bow the back gets hot = dry.  The outer surface of the wood is where it is the driest and dry wood becomes brittle in tension hence a tension failure.
V true.
I usually try to protect the back if possible, supporting the bow on a narrow plank edge rather than a 3x2, allows heat to blow past the back, a few layers of tape can help too
Sometimes clamp thin slats to the sides of the bow, this helps direct heat along the belly, (which can speed up the process a tad) as well a keeping it off the back.
Having said all that, it is hard to stop some leakage of hot air (happens when ever I open my big mouth ;) ).
I especially take care with Yew... don't want to disscolour that pretty sapwood :-*
Del
Title: Re: Waiting after tempering, how long?
Post by: Tom Leemans on December 11, 2013, 12:32:35 pm
Something, something, err on the side of caution, something..... That has always been a good policy, and until someone has been kind enough to amass all the scientific data and publish it, that's a pretty sound policy.  I have yet to see such data because we're all too busy enjoying our bows. ;)