My new bender (so far)

[johnnyg]

Coming to the end of building my side bender. This is mostly from plans Ken sent me so there are no real surprises. There are 3 200 watt bulbs and a timer from the local home store. It's lined on the inside with aluminum flashing from the same home store. The top is the same flashing held in place with 1" wire nails and sealed with aluminum tape rated to 800 degrees.

I fired it up tonight to see how well it heated. It didn't seem to me to have enough heat after about 20 minutes but I am not sure what to expect. The base is 6" tall so it's about 2" taller than the top of the bulbs. The L-00 form sits on top of that. Should the base be smaller? Maybe 4" tall so the bulbs are closer to the bending surface?

The hardware is proving to be the hardest to obtain. The local home store doesn't have much on hand and not really any other options in the remote hill of NC. I will either adapt something or head to the big city.

Any and all comments and advice are welcome!

[Dave Bagwill]

There are plans?

[johnnyg]

i have attached pics. I can't figure out how to embed them in the post.

Yes, there are plans. Ken sent me ones of a bender I think he used to sell. If he doesn't post them, I can send you a copy.

[Kevin in California]

Johnny, I have a light bulb bender on the Fox design, 3 @ 150 watt bulbs, and it gets up to 350 degrees in about 15 minutes. Have you check out how hot yours is getting with a Thermo?
You can get an inexpensive thermometer with a probe at a Walmart for less than $15, and it is accurate enough for this work.

[johnnyg]

I have not checked with a thermometer. I will pick one up today. it was just a guess that it did not seem that hot. I could be way off base.

[johnnyg]

Ok, I reworked the bender. Cut the base down so its the same height as the top of the bulbs about 5.5". Put aluminum tape inside instead of the flashing because I didn't like the way it fit. I splurged and got an infrared thermometer. When I fired it up it started climbing quickly to 125 degrees. Then it took about 30 minutes to get to about 150 and basically leveled out there.

My feeling was heat was dissipating from the flashing on the top as quickly as it was heating at that point. So I laid my heat blanket (4x5) in the waist (not turned on) and put a digital thermometer with a probe between the blanket and the form. After about 15 minutes the temp under the blanket rose to 230. This seems to confirm my theory of heat dissipation.

So, any ideas on where to go from here to get this heat up? Will this problem take care of itself once I have the wood on it?

Thanks for the help!

[ken cierp]

Do you have a reflector on top of the light bulb bases? Its should be a metal plate with holes just large enough to screw in the bulbs (this is a safety feature as well). I recommend at least 600 watts -- even 700 using a 300 watt at the lower bout. Clear bulbs work best. Using the pre-bend at the waist strategy I've bent all the common woods at around 250 degrees, as long as it makes a bit of steam its good to go. Again the trick if there is one is thinning to about .075" (same as the Martin factory) and pre-bending the waist curve. Survey our KMG kit builder's I bet they will confirm our sides are bent very accurately with very little spring back.