Something new in the workshop-Steam box

rtibbs

rtibbs

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Decided to give steam bending a try so I constructed this steam box
It's 32" in length with an inside of appro. 5" x 5" made of pine.
I know, the thermometer is a tad large but it's something I had from a previous job. What the heck, I can see the temperature from across the room.

Side view.jpg
Added a handle for ease of carrying


Inside.jpg
Oops, forgot to clean the dust out.


Logo.jpg
Always carve my logo on my projects although generally a little smaller and less conspicuous :rolleyes:
Using the Rockler unit for generating the steam. Hose connection is in the back end of the box.
 
rtibbs said:
Decided to give steam bending a try so I constructed this steam box
It's 32" in length with an inside of appro. 5" x 5" made of pine.
I know, the thermometer is a tad large but it's something I had from a previous job. What the heck, I can see the temperature from across the room.

View attachment 309105
Added a handle for ease of carrying


View attachment 309106
Oops, forgot to clean the dust out.


View attachment 309107
Always carve my logo on my projects although generally a little smaller and less conspicuous :rolleyes:
Using the Rockler unit for generating the steam. Hose connection is in the back end of the box.
Click to expand...
That's a very nice looking steam box rtibbs,

I am guessing the small hole in the door is to allow steam out, so pressure doesn't build up too much.

Cheers,
Stephen.
 
rtibbs said:
Hummm, I guess I need to work out some new Rules of Thumb for steam bending. Rule of thumb for bending is 1 hour per inch of wood. So 1.7 mm thick = ? :)
Click to expand...
Hi rtibbs,

I am sure you will work out a procedure/rule of thumb.
I found that my hull planks which were about 2.5 mm thick required 10 to 15 min in my steamer to become supple, the only down side is they cool quickly and once cool are not as supple/bendable, so speed is the essence.
I also would start bending the plank in my fingers as soon as it was removed from the steam.

One small thought is I made a crude tray from mesh to sit the planks on, this allows me to slide the tray with planks into and out of the steam box using a hook or long tweezers without burning my fingers as much.

Cheers,
Stephen.
 
Oh well, back to the drawing board. I really liked the results when bending steamed wood. With my 1.7 x 6mm strips I was steaming them for about 10-15 minutes.
Everything was going just fine on my second day right up until the time the steam box decided to split in two :eek:
So much for New Zealand pine. ;)
Not sure if my vent hole was not large enough as it split right down the center of the top piece inline with the thermometer and screw holes attaching the handle.
(Can you say stress points)
Maybe I will add a pressure gauge on the next one :)
This one was made from 3/4" clear pine and thought I would make a second one from Baltic Birch plywood. Oops, vendors have stopped buying from Russia.
 
Hi rtibbs,

That is disappointing, do you mean it completely split in two as in a catastrophic failure or was it mainly a split along the board with the temp sensor?

My guess is maybe the temperature sensor might have been a bit tight in the hole leading to the split, just a thought.

Maybe some sort of repair like straps around the box?

What did the steam coming out of the exhaust/vent look like, was it coming out horizontally for quite a long distance which would indicate fairly high pressure?

Cheers,
Stephen.
 
I found that the steam hole out should be about the same size as the hole in. You don't really need any pressure for the little stuff we steam. As long as the temp goes to 212f(100c) you're golden. I think you've also learned the lesson that there is no point in making a fancy steam box. They are consumables if made from wood. An ugly piece of PVC or ABS is the answer.
 
Don Case said:
I found that the steam hole out should be about the same size as the hole in. You don't really need any pressure for the little stuff we steam. As long as the temp goes to 212f(100c) you're golden. I think you've also learned the lesson that there is no point in making a fancy steam box. They are consumables if made from wood. An ugly piece of PVC or ABS is the answer.
Click to expand...

Thanks for your input however, I try to avoid ugly.
 
rtibbs said:
Oh well, back to the drawing board. I really liked the results when bending steamed wood. With my 1.7 x 6mm strips I was steaming them for about 10-15 minutes.
Everything was going just fine on my second day right up until the time the steam box decided to split in two :eek:
So much for New Zealand pine. ;)
Not sure if my vent hole was not large enough as it split right down the center of the top piece inline with the thermometer and screw holes attaching the handle.
(Can you say stress points)
Maybe I will add a pressure gauge on the next one :)
This one was made from 3/4" clear pine and thought I would make a second one from Baltic Birch plywood. Oops, vendors have stopped buying from Russia.
Click to expand...
My $.02:

I doubt it was a pressure issue. If you want to put a gauge I'd suggest one in the Inches of Water range rather than PSI/BAR. ~27"H2O=1PSI. Magnehelic makes good ones available from Grainger, but they're not cheap.

I believe the problem was likely due to applying steam to only one side of the (I assume) kiln dried wood. The expansion of the wood on one side due to the moisture and heat + the stress points you pointed out was just too much for the wood.

If you are considering plywood I would do a test to insure the glue between the laminates will withstand the steam.

That is a very nice looking box!

Glenn
 
I think Glenn is right. I plan to make my steam box out of PVC trim, like Versatex. I have a small supply of 3/4" left over from some exterior work on the house.
 
An alternative to the gauge you can use a manometer. Easy to make for little $. Google "diy manometer". Be careful, might learn some science ;)

Glenn
 
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