Primitive Archer

Main Discussion Area => Bows => Topic started by: Selfbowman on November 19, 2020, 09:50:48 pm

Title: Thermomelt stick??
Post by: Selfbowman on November 19, 2020, 09:50:48 pm
Guys I was with a bud helping extend his work shop. He is a welder. He gave me a thermomelt stilck. They use it to test the heat on metal during a weld  . Accurate within 1%.  You mark the surface and if temp is right the mark melts away. Could this help in heat treat the belly? I will do some experiments when I get a chance. Arvin
Title: Re: Thermomelt stick??
Post by: Morgan on November 19, 2020, 10:27:37 pm
The ones we use at work are to find overheated dies and don’t mark until the surface is over 550°. Hotter the surface the more the stick “flows” for lack of better term.
Title: Re: Thermomelt stick??
Post by: mmattockx on November 19, 2020, 10:43:19 pm
Could this help in heat treat the belly?

It might, but I would be concerned about the stick material contaminating the wood and messing up a finish. The big question is how surface temperature relates to the core temperature of the wood. If you had a procedure that you already know works then you could correlate the surface temperatures that procedure produces with the results you want deeper in the wood and use the marker to gain some consistency with the process.

For anyone who is interested in these, the generic description for them is 'temperature indicating crayons' and they come in a huge range of temperatures from ~100F to 2500F. Searching on that term will find piles of info. The brand I am familiar with from work is Tempilstik, but there are numerous suppliers out there.


Mark
Title: Re: Thermomelt stick??
Post by: bownarra on November 20, 2020, 01:10:17 am
I can't see it of being any practical use? It isn't necessary to know the temps during heat treating but if you really wanted to then just buy a laser therometer.
Title: Re: Thermomelt stick??
Post by: HH~ on November 20, 2020, 07:59:46 am
If you going to scrape belly more after some heat I dont see it doing anything to wood. Be a quick way to know when you have reached temp to get an even heat Arvin. Let me know how it works out.

Shawn~
Title: Re: Thermomelt stick??
Post by: Badger on November 20, 2020, 09:59:31 am
 If I was going to use something like that I think I would heat the belly until the back hit about 212 degrees or so.
Title: Re: Thermomelt stick??
Post by: Bob Barnes on November 20, 2020, 10:22:19 am
just decide what temp you want to heat the belly...get a stick made for that temp...you can buy one for 250° if that's what you want.  I would think one made for welding would be 10 times that high.
Title: Re: Thermomelt stick??
Post by: DC on November 20, 2020, 10:46:11 am
It will just tell you the surface temp which is handy so if it's cheaper than a thermometer go for it. The problem being with either is that if you hold the heat gun close the surface will reach 400° way faster than if you hold the gun further away. It's the temp inside the wood that we're interested in. I think Badgers method is the way but that's hard to use when you have the bow on a caul.
Title: Re: Thermomelt stick??
Post by: bassman on November 20, 2020, 11:22:29 am
We used what we call temp sticks as a temp guide, and to get metal up to pre heat temp in order to start welding on it with out cracks forming, and we had them from 250 degrees ,and up. Don't know   if the temp sticks would be beneficial ,or not for what we do.I go by a moisture meter now since I bought one. Yesterday I reduced,and put 2 green  white Oak floor tillered bows on forms ,and measured the moisture content on the bellies at 25 to 26 percent. Over night they dropped to 22 percent. When they  settle in my basement  moisture wise I will stick them in a hot box for a week , or so ,and heat treat the belly with a heat gun, and maybe fire harden them ,and the start the tillering process. Second part of my reply was off subject, but may help some  on here to deal with moisture ,and set.