Monday, April 28, 2014

Hot Stuff

I recently rebuilt my larger steambox that I use for classes. I had such good results using the two steamers and insulated boxes in Atlanta and North Carolina, that I wanted to see what I could do.

Here is the box that I made. I used a tongue and groove that ran the length of the box to seal the sides and Gorilla glue to seal the joint. Since this photo, I've added a proper hasp.


The insulation is 1 inch thick foil faced and is just draped over the box. Without the foil face, the insulation will swell and warp. With this set up, and insulation on both ends, I was able to get the box up to 210.5 degrees f. With 212 degrees being the absolute highest that the temp can get without being pressurized, I call this a success.


When we opened and closed the door to retrieve the bends, the temp only dropped about 6 degrees and recouped the heat within minutes. One thing that I noticed was that one of the two steamer units went through water much faster than the other, and so I checked the wattage. Sure enough, my older one was 1250 and the new one that I bought at Highland was 1500. While the bends came off beautifully, I can only imagine that two 1500 watt units would be the ideal. Keep in mind that this box is 9 by 11 inches so that it can hold a whole class worth of parts and must keep the heat up with lots of door openings. On a smaller box, one unit is fine, especially if it's insulated.

9 comments:

Brandon said...

How important is it to contain the steam? Are there any holes in your box to vent? I spent hours trying to seal my steam box from any steam release after breaking 3 continuous arms, all rived from a green white oak log. I'm beginning to think maybe I WANT some steam to escape. I plan to add a steamer also, as I'm only able to get the temp to 195. Maybe that's my issue.

Thanks for being a great resource.

Peter Galbert said...

Brandon,
yes, some steam escaping is good, otherwise you will be relying on conduction instead of convection. I think that you will find that the extra 15 degrees makes a difference. I do have a hole in the lower side to drain and the door leaks a little. Let me know if the other steamer makes a difference.

Anonymous said...

G'day Pete, did you ever get around to comparing the wet steam verses the dry steam bending method and which are you using here, see you in OZ, Mim

Peter Galbert said...

I have not had a chance to do the comparison. For now, I've simply cut the distance from the steamer to the box and added more insulation to the piping to make sure that the maximum amount of moisture stays vaporous. With the success of the steamer as is, it will most likely be some time before any further experiments.

Anonymous said...

i know this for a fact from losing about 8 c-arm bends before I figure out the problem. - the steam HAS TO escape.
It seemed to me that if the box was sealed and therefore somewhat pressurized that it would "push" the steam into the wood better. so after I would close the box I would wrap it in saran wrap to seal it. I could not get it to bend. I thought it was the wood. I tried three different logs. still catastrophic failure.
one day I didn't have any saran wrap and guess what, the wood took the bend. so the moral of the story is don't worry about sealing the ends of the box. if the steam is coming out of the ends of the box then your doing it right.

Bill Palmer said...

Hey Pete: Where did you get the digital termometer. Not to split hairs(yeah right) but you also had me use pipe insulation from the steamer to the box.
My latest experiment was to build a smaller box,ran the steam hose into a reservoire which then fed the box( can't remember where I got that Idea...oh yeah..you!). My temps were close to 200 and the balloon backs bent beautifully(3). I'll insulate the box to see if there is a difference.
Best, Bill

Peter Galbert said...

Bill,
yes, I insulated the piping on this one as well. I think that you will find that the insulation will make a visible difference. The thermometer belongs to a friend, but I'm sure a quick visit to Amazon will find one. the brand name is frio temp. It has a metal wand for the sensor.

Bill Palmer said...

Oh yeah, a digital meat thermometer would work, I think.
Bill

Peter Galbert said...

Bill,
the thermometer I am using is precise. I'm not sure if a meat thermometer, meant for contact would work as well measuring ambient temp, just a thought,
Pete