Heat gun

[Don Case]

I got a heat gun for Christmas and I have a question. Most of the posts I have seen show people using a jig that holds the gun about 4" off the bow and they move the gun every 5 mins. or so til the job is done. To me this means that if you move the gun 5 times you probably have 5 hot spots. A few have said that they stand there and wave the gun back and forth until the belly is evenly brown. This seems like it would do a better job to me. Is there a marked difference between the two methods? I can see the jig method being a whole lot easier on old arms but I can also see the possibility of wandering away. The name Del pops to mind. Comments anyone?
Don

[BowSlayer]

I, used it on a bow to reflex one limb to match the other. I did it in patches but moved it along I broke the limb into three sections and kind of overlapped them. it worked for me. hope this helped.

[Danzn Bar]

Don,
I do my dry heat by hand and move it back and forth for about four inches at a time.  A big caution with dry heat and major bends or straighting with a heat gun is "take your time" and put the heat gun on the lowest setting.  I do some steam heat bending and the temp is only about 212 deg F. but the soak time is 45 min to an hour.  My steam bends turn out great.  With dry heat you have a tendency to rush and get the surface too hot and when bending the surfaces breaks and or raises splinters.  I think 230 to 250 deg F soaked all the way through the wood works bests.  Adding oil with dry heat helps but you still need to keep the temp low and do not attempt to bend the wood until a good soak is complete.  Just IMO......
DBar

[Pat B]

Marc St Louis popularized the belly tempering method with his chapter in TBBIV. Marc uses a jig to hold the heat gun so he can get the deep tempering he desired. I hand hold the heat gun and work from the handle out towards the tips heating about 6" at a time to a chocolate brown. As one area is done I move out to the next 6" but keep the previous 6" hot with the heat gun. When the whole limb is treated I go back over from handle to tip reheating the limb. When both limbs are done I let the bow rest in the form for 3 to 4 days to a week to rehydrate from the heating, depending on the R/H at the time.

[Danzn Bar]

I do what Pat B said to temper bellies......

[Marc St Louis]

Actually Pat I made the process popular with the first few articles in the PA magazine back in early 2000. 

I actually started out heat-treating with a hotplate, the heat-gun was a big improvement by making it easier but the results were the same.  You do get these slightly darker "spots" but it doesn't seem to make a difference in the end result.  If you are meticulous you can minimize these spots to the point where they don't show, this means moving the heat-gun a lot more than 5 times.  I probably move the gun a dozen times per limb

[Don Case]

I played with it a bit last night and now I'm going to build a jig. Standing there holding the gun for more than 10 mins turns out to be my limit. More boredom than tiresome. I'll need something to read.

[Don Case]

Before I make the jig, is there any advantage in tilting the gun to aim the hot air in the direction of travel? Also I was reading the instructions(go ahead call me a wus ) and I saw a "flare nozzle" that narrows the air blast. Would that help keep the heat from wrapping around the bow?

[burchett.donald]

 A pic of my 2x4 heat gun jig...

[Marc St Louis]

I used to use a 2X4 until I heat-treated a narrow HHB warbow, the first HHB warbow I ever made back in 2003.  The heat from the gun bounced off the 2X4 and "burnt" the back of the bow along the edges.  Even though it didn't seem to hurt the bow I didn't much care for that so I narrowed the 2X4 to 1" in width.

[Gordon]

Here is a picture of the setup that I use for simultaneously heating in reflex and tempering the belly of a bow.

[Don Case]

Do you have a lot of cawls or does one size fit all?

[Gordon]

I have a couple of different cauls, but the one in the picture is the one I use the most frequently.