Hot box modifications

[R.W.]

For all you experienced laminated bow bowyers.

Would placeing a small fan (such as one from a computer power source) in the hot box, give a better, meaning a more uniform heat, curing environment for the new bow.

I would think that using incandescent lights would have the top of the hot box at a higher temp than the bottom. A fan, by circulating the air, would equalize the temperature top to bottom, ridding the box of hot spots, and cool spots.

Also, has anyone tried "vacuum bagging" thier bows before placing them into the form. The "vacuum bag" should preclude air entrapment in the laminations/glue, making for a stronger, and better appearing finished bow.

[R.W.]

ttt

[kennym]

The fan couldn't hurt,but I don't know if I could keep the lams where I wanted em if they were vacuum sealed./?

[mjlaychur]

why?  Mt hotbox works fine without a fan.

[OconeeDan]

Well, I am no expert, but my hot box with lightbulbs has worked fine without a fan.  A zillion shots and no problems.
Also, I have only used the pressurized fire hose system, and have never had a bubble.  Not the tiniest.
I am doubting that a vacuum bag system can apply 60 psi to the laminations.
Just my thoughts, like I said I am not an ekspurt.
Dan

[twisted]

Hey RW i had the same idea about the fan but what i came up with was to use a regular 80mm pc fan mounted on the inside of the lid and a piece of flexibale dryer hose and the wall adapters on the outside to channel the hot air back in but at the bottom since the lid is way hotter on heat box it gets up to 187%f but i have 2 5oowatt helogen worklights in it he he.
If u want i can doodle u a pic so u know what i mean for the fan idea
 PS where in canada u from im in southeren Ontario

[BarryOnly]

I also use my hotbox to dry staves since my basement is too humid (I dabble in both laminated and self bows).  I rigged a fan to keep the air moving.

I have a passage at the bottom of my hotbox that has a 4" duct fan which blows the air over 4 incandescent lightbulbs.  There is a hole at the end of this passage that goes into the upper portion where my lam form or stave is, and there is another hole at the opposite end for the air to recirculate back to the fan.  I also have a container of salt to hopefully trap any humidity that recirculates.  The inside is lined with reflective aluminum insulation.

I have hinges for both parts of the hotbox so that I can access the bulbs.  It may be over elaborate, but it will dry a roughted out stave pretty quickly.

[V-Archer]

I have a fan in my heat box that circulates hot air. I constructed the fan housing such that it circulates the hot air through the fan sytem again so that the temperature remains stable inside the entire box. I use "shower" heater elements (2x 250 Watts) as heating source. (thermostate controlled) The walls are covered with an aluminium coated cloth material.

V-Archer    

 

 

 

[Glenn Newell]

I have cured a lot of bows in my hot box but for the last 60 odd bows I have used I have used a heat gun in the box to circulate the air. It works real well but I do turn off three of the lights because it get too hot...Glenn...

[ChuckC]

Don't know if there is a real need or not, regarding end heat distribution as the space is small, however the heat will be distributed faster with moving air (convection vs conduction) and maybe that can cut down a bit on time needed in the box.   Just a thought
ChuckC

[iacornfed]

R.W. you must be a boat builder. Thats about the only people I hear of that mention vacuum bagging. I think it would work well.

[R.W.]

HA! Another idea that is already being used!  

Twisted, I hail from South Eastern Alberta.

iacornfed: Well, I have to admit that a boat is one of a few things I haven't YET built!  

I actually got the idea from R/C plane building (gliders) where the builders are vacuum bagging the wings and fuselage so that they are smooth "as glass" and no air entrainment takes place. I believe this is for strength, and my thought was that this *might* work for laminating bows, as well.

[SOS]

I guess I need to start turning the recirc fans on in my hotbox.  When, cooking limbs on a hot summer day in the old 1991 Volvo in the driveway, should I turn on the fan AND the radio while I'm at it?  :rolleyes: