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PostPosted: Wed Dec 07, 2011 7:28 pm 
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Location: Visalia, CA
Yep, it is. That's why I need to enclose the form, surface got to 300 degrees when closed up....that should be hot enough.


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PostPosted: Wed Dec 07, 2011 7:29 pm 
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Location: Hegins, Pa
I also forgot to tell you that you can use a little fabric softener in the water. 1 tbls per qt is plenty .. Use a med heat , you will see that within a minute or so the wood will get ready to bend

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Blues Creek Guitars Inc
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http://www.bluescreekguitars.com


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PostPosted: Wed Dec 07, 2011 7:36 pm 
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Location: Bothell, WA USA
I picked up one of these "Automotive" multi-meters at Harbor Freight on sale.

http://www.harborfreight.com/lcd-automo ... 95670.html

It has a k-type thermocouple that is the thickness of a small gauge wire, and is quite a bit quicker responding to temperature changes than the the cooking thermometers I was using.


They are $40 plus shipping, but if you can get one of their coupons (I got mine 30% off) and pick it up locally to save shipping, it's not a bad deal....

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PostPosted: Thu Dec 08, 2011 11:00 am 
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Location: Visalia, CA
I enclosed the dred form last night with 26 gauge galvanized. My plan is to have one of the .008" SS slats under the side so the galvanizing won't touch the wood. I want to see 300 degrees on the thermo before I lay the wood on the form and start bending.
Tonight I test it out again, I'll post the results when done. Wish me luck.

Kevin


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PostPosted: Thu Dec 08, 2011 12:59 pm 
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Location: Visalia, CA
Right you are Ken,
I apprenticed as a sheet metal mechanic (a LONG time ago), but it is good to be reminded that there are hazards associated with heating metals, especially galvanized. I'm not planning on torching it, now that is a recipe for concern.

Kevin


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PostPosted: Fri Dec 09, 2011 2:24 am 
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Location: Visalia, CA
Success!
Here is what I did....a recipe that worked!
1. I clamped one SS .008" slat down over the form which is now covered with 26 gauge galvanized. Sorry I forgot to get a picture of this. I preheated the form up to 300 degrees. This took 50 minutes. A long time. I'm using 2 x 150 watt and 1 x 200 watt bulbs.
2. I soaked the side for 30 minutes in the bath tub. Took it out and let it sit for the remaining 20 minutes it took for the form to heat up.

3. It took me about 3 minutes to unclamp, insert the side, put the other slat on top, and secure the waist support bar. I then moved the thermo probe from under the bottom slat and inserted it into the conduit form separator near the waist to continue to monitor the heat. Then I mounted the bout clamping cauls with the springs on either side of the waist.

4. There was a slight sizziling going on as I slowly screwed down the waist caul, I did this until it was down all the way, then backed it off about a quarter inch.

5. I bent the upper bout first, going slow, pushing the side down with my leather gloved hand to make contact with the form, and as it gave under slight pressure, I moved the clamping caul down a bit. It took about 3 minutes to get the upper bout bent. The temp rose to 345 degrees while I was bending. Then I lowered the waist caul back down tight again, and started bending the lower bout the same way, and it took about the same amount of time. The whole bend took around 10 minutes.

I reset the timer to cook the side for 30 minutes. The temp reached 339 degrees and shut off.

The whole process, start to finish when I shut the light bulbs down was 1 1/2 hours. Then a cool down of one hour.

The side thickness was .080", and felt pretty flexible before wetting it.

I let it all cool down to 90 degrees, then took the side out and placed it in the mold. A perfect fit!, and almost no spring back. I got quite a bit of staining that should scrape and sand off.....at least I hope so. I was very pleased that this worked. Perhaps the bend would have taken place fine without soaking, but after doing so, I really don't have anymore staining then I got on the previous side I tried, spritzed with water and wrapped in paper, so I think I will proceed with the two REAL sides with this same program. First I will sand a scrape a bit on this practice side to make sure the stains can be removed.

One change I will make is.....put 3 x 200 watt bulbs in there which should let it heat up a little faster, and get just a little bit hotter..
Here are a few pictures. I forgot to take one with the wet side laying on the form before starting the bend, but you all can picture that in your mind, right.

I will go for reals on Saturday and try and get both sides bent.

Kevin


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PostPosted: Fri Dec 09, 2011 2:26 am 
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more pics


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PostPosted: Fri Dec 09, 2011 2:27 am 
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more pics


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PostPosted: Fri Dec 09, 2011 2:29 am 
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more pics

Kevin


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PostPosted: Fri Dec 09, 2011 7:53 am 
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Location: Hegins, Pa
No need to soak . With a light bulb bender the heat comes from within. You have a lot of water staining. Use a spray bottle and damp paper .

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Blues Creek Guitars Inc
Authorized CF Martin Repair Center
Board of Directors of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com


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