Portable lighter bow oven?

[Sant-Ravenhill]

Years ago I built a heat box/bow oven out of plywood. It worked great but is now gone. I sold my house, in a rental and will be moving in a year. I would like to make a bow or two this winter.

I want to make another bow oven but I would like it as light and portable as possible as I will be moving it up and down stairs. I was thinking foam board, styrofoam insulation, or? Possibly a light 1X pine frame for strength? Or much better ideas?

Thanks for your time...Brett

[mmattockx]

Depends on your desired temps, but I have seen it mentioned here that some use an electric blanket laid over the form with a heavy comforter over that to keep the heat in. I think that will get you into the ~120F range with little trouble.

If it needs to be a box I would suggest a light wood frame with panels made from heavy cardboard. The cardboard will survive much higher temps than the epoxy will with no issues at all.


Mark

[Pat B]

You can build a hot box with foil backed foam board held together with duct tape and ceramic light sockets and 100w bulbs for the heat source.

[Sant-Ravenhill]

A couple of good ideas...thank you. If anyone else has some thoughts please post. Brett

[Longcruise]

A refrigerator box?  It could be folded flat when not in use.

I do a variation on the blanket trick by putting a blanket over the form with each end slightly open and blow a space heater through it.  Temperature is monitored with a Bluetooth meat thermometer.   I run it at about 135*  for 12 or more hours then turn off and leave it overnight.

Then there's the car in the sun trick if the season and climate permits.

Another is to wrap it all up in black plastic and lay it in the sun.  Just don't lay it on the grass.

Finally,  you don't need any oven contraptions at all.  If kept at room temperature (my definition is 72*) and allow at least 24 hours.

I've used all of the above except the refrigerator box and they all worked.

Good luck with your tight quarters building.   It's been successfully by others.

[onetone]

The oven is expedient, but not essential to building a durable, quality bow.

[Roy from Pa]

The electric blanket with another blanket over it is your easiest way to go. And its already been mentioned that epoxy dries in 24 hours at room temperature at 70 degrees. The heated blanket will get 110 degrees easily.

[Shredd]

  i use an electric blanket with a sleeping bag over top...  i get 110 to 120 degrees...  plenty of heat to cure a bow... 

[Sant-Ravenhill]

Thanks to all. It sounds like an electric blanket is the simplest way to go. I have more than one old sleeping bag to cover it with. Though the refrigerator box or foil backed foam board are serious options for a more structure oriented bow oven.

I've always read that you want higher heat to cure or there is the possibility that the limbs will delaminate. Any truth to that or is it like onetone posted, expedient but not essential?

Thanks again! This is one of the reasons why I love this website.

[Sant-Ravenhill]

TTT

[kennym]

Supposedly the higher heat will keep from delamming up to that temp, I  haven't seen proof of that but have seen a heat delammed bow.

I had heard some big name bowyers weren't heating so I built my bro and I a pair of TDs without heat to test,
 cured at 70* in the shop.

That was 4 years ago and no probs yet, but we don't leave em in a hot car or  anything like that.

Mine has been left in the truck on a few warm days ,80ish, but I roll the windows down a bit.

[Flem]

You can use 1/8" plywood and glue/laminate some rigid foil faced insulation to it. Makes a stiff panel that is reasonably light. Plus you can crank the heat up to 200deg if you want.

[Longcruise]

You can use 1/8" plywood and glue/laminate some rigid foil faced insulation to it. Makes a stiff panel that is reasonably light. Plus you can crank the heat up to 200deg if you want.

Good idea.   Maybe sime hinges to allow folding it up?

[wood carver 2]

I used a padded moving blanket draped over some f clamps over my bows and a small space heater placed just outside the open end with the blower on high.
My heater is the ceramic type with no glowing red hot elements. I stuck a meat thermometer through the blanket at the far end and it read 160 degrees.
Dave.

[Forwardhandle]

I only use 2 electric blankets and 2 clip on shop lights to cure my bows you can go between 125-200 F the only problem is you really have to watch it tell you get your temp stabilized I usually cure between 125-150 F I have a controller kit for it I never put together , and when your done fold it up and put away ! I have room temp cured bows to with out issue !

[Longcruise]

I would room temp all of mine but in the cold months I can't count on keeping the room that I'm "allowed" to use at 70 degrees minimum. 

[Flem]

Epoxy will cure just fine at 70deg. Even at lower temps, within reason. Just have to double the time for every 18deg in temp change down and half it for every 18deg up. The prime reason for cooking bows is to cut production time. If you are brave enough to ignore the EA-40 cure schedule, you can have a bow cooked in 45min @ 160deg. Of course you have to start with room temp materials and factor the cool down period. I always put a dummy wood block with a temp probe in the center, in with the bow blank to get an accurate idea of the internal temperature.

[Sant-Ravenhill]

Great information...thanks again to all that have posted. It has saved me lots of time experimenting from scratch. I will keep you posted on what I end up doing and the results.

[Shredd]

here is something else to consider...  i call an electric blanket gentle heat... meaning it heats up slow and evenly...  if you don't heat your form up evenly you could warp it...  i have heard of this happening more than once...  if you want to take an extra precaution you could put plastic over the form before putting the blanket over it to help maintain the same moisture content on all sides...

flem... my school of thought on temperature is to give it enough heat so those molecules can get moving and interact properly...  meaning get the temperature above ninety degrees...

[Flem]

Thats a really good point Rich. I should be qualifying any statements I make, because I do not use a form and don't know about any affect my heating schedule might have on one.