steam box problem

[wharfrat]

I’m having problems filling my steamboat with steam let along getting the temp up between 180 and 200 degrees. I think it may be that the water isn’t boiling furiously enough. Da ya think? I bought one of those hot plates with two burners with a combined wattage of 1500 watts. I used a rectangular pot that covered both elements but once it came to a boil an hour later the temperature was only a little over 100 degrees. I tried a small dia hose (garden size dia), then a rad hose dia., I tried only a few inches of water thinking it would be a more rapid amount of steam. I tried filling the pot almost full thinking that the steam might be forced out more.

My box is 6 inch by 10 feet PVC. I stuffed both ends with a towel. I understand that the box needs a flow but I sealed it fairly tight at least until it was to reach the appropriate temperature then I was going to let a bit of the steam escape. I have the inlet in the middle of the PVC pipe. The hose is about 16 inches long. There is no steam escaping until it gets to the PVC pipe. I would have thought that once water is boiling then the rest should fall into place. But after a couple hours of boiling, the pipe isn’t even full of steam. It looks more like a London fog in there.

My next try is to go to an appliance store and purchase 2 of the large elements for a stove and built a steel box for them to sit in and give that a go. I’m wondering if a 15-amp breaker will be enough for them on at the same time through one plug?

I’m allergic to propane or butane of any other form of gas. I suppose I could get a wood stove rigged up but the time involved and waste of the forest doesn’t seem necessary.

Any suggestion?
Thanks

[P.I. Stazzer-Newt]

You got a centigrade thermometer?

[JimD]

I understand that the box needs a flow but I sealed it fairly tight at least until it was to reach the appropriate temperature then I was going to let a bit of the steam escapeMe no expert but this does not sound like the right approach. Hot steam has to be able to flow through and out of the box before it cools, and let new hot steam in. Also, it sounds like you need more heat, more steam. I have only used a small three foot long box for steaming oak hoops and I use a wide open burner on a propane tank for heat.

[Bruce Hooke]

I agree with Jim, the steam won't be able to get into the box if there is nowhere for the air in the box to go to get out of the way. So, do provide a bit of ventilation from the start. That said, I suspect your heat source is not up to the job at least as currently configured. I do my steaming in a pine box that is about 6" x 8" x 48" and my steam source is two standard (2 quart?) cooking pots on a gas kitchen stove. Both pots are kept at a good boil. You might try switching from that big rectangular pot to two smaller cooking pots. A large pot takes a LOT more heat to keep at a boil than a smaller pot. The downside is that you need enough water in the pot to finish the job. What I do is keep a third pot on a simmer at the back of the stove and as the main pots get low I top them up. DO NOT try to top up your pot with cold water. If you can get the water in your source pot to a rolling boil and keep it there then I think you will be set on the steam generation end. It needs to be a rolling boil, a light simmer won't do it.

[Norman Bernstein]

I had a lot of success, some years ago, by using a Coleman camping stove, the kind fueled with 'white gas'. My steam generator was a new metal gas can... with thinwall rigid tubing, about 1.5" dia, hoseclamped to the can, and to fittings on the PVC 'steam box'. I let the steam flow freely until the vapor was plainly visible coming out the open end... and then I stuffed a rag into the end to partially restrict the exit.

[ssor]

Steam = 1000btu/pound
1Kilowatt= 3000btu
1500 watts = 4500 btu
If your boiler efficiency is 100% then you can convert 4.5 pints of water into steam per hour. At the very least your towels should be getting wet.

[wharfrat]

My towels weren’t even damp SSOR. Your calculations tell me I need more heat. I neglected to mention that the towels were loose fitted enough to let a margin of steam escape from the ends. At one point I made an opening in the towel big enough to fit a tennis ball through with no difference in my steam flow.

[NormMessinger]

Maybe insulate your steam box and steam lines.

[Siebert]

I built a steam box from PVC and it failed also. I was using a turkey fryer propane burner (45K BTU) and a 4 gallon stock pot with an adaptor lid that hooked to a 4" flexible metal dryer duct and then to the PVC pipe. My problem was that when I got the thing up to temp and was blowing plenty of steam out the vent hole I cut at the far end, the PVC would soften and sag as the wood softened and became flexible. I fiddled around attaching it to boards, putting more saw bucks underneath, and in the end, bit the bullet and built a proper box out of some 1/2" CDX plywood wrapped with some R-14 foil faced insullation. Total cost for the better box $40. No complaints since. My box is 8', and is screwed together so that when not in use, it can be disassembled and stored flat.

[ssor]

When I was in high school I attended a new school that was incomplete when the academic year started. The machine shop needed the machine tools cleaned and painted, the heating system for the building was almost complete and the steamfitters were purging the lines. We needed hot water to wash the machines and there was a steam vent hose on the ground outside the back door. It was blowing a cloud of steam twenty or thirty feet long. We filled a five gallon bucket about a third full of cold water and stuck that steam hose into the cold water. We expected a lot of action with spitting and sputtering and splashing. You can only imagine our astonishment when the steam plume disappeared and the bucket slowly filled with hot water. The steam simply condenced in the cold water. You don't need to provide a steam vent so much as you need a condensate drain.

[ 03-16-2005, 04:49 PM: Message edited by: ssor ]

[NormMessinger]

Steam is invisible.

[ssor]

Originally posted by NormMessinger:
Steam is invisible.Picky, picky, picky. :D

[Steve Miller]

Based on earlier postings here I used a $39 garment steamer from Home Depot. I stuck a piece of 1" heater hose in the outlet and used a piece of aluminum dryer duct for my "steam box". Bits of wire coat hanger stuck through the duct held the wood off the bottom of my pipe. The pipe is duct taped and wired to a 2x4.

The steamer runs for 40 minutes on a fill but its fast to re-fill and since the unit generates steam in 45 seconds there is never even a lapse in the steam venting out of the far end of my steam box. I lay old towels over the pipe to insulate. Just used it again last weekend. Plenty of steam - and the rags plugging each end get really hot!

http://www.hevanet.com/kg7pv/Utility/image24.jpg

[Ed Harrow]

Somebody, Eric Taube??, made a steamer using bits of plumbing and a "burn-out proof" waterheater element. I can't think of the name of the book, but I think I'm pretty close to having the author correct.

Also, our own, brilliantly clever Ken Hutchins rigged up a neat in-situ steam "box" using some kind of tubular plastic bag material. I once had pictures of it (they were on my long-gone website).

[Ken Hutchins]

Ed, I saved some of the photos.
Here is a 2-1/4 square rib being steamed in a polyethelyne bag. The bag system works great because there is no rush to get the part bent, keep the steam flowing until the bending is complete I even stopped in the middle of a bend for an important phone call while bending one of the ribs. There is no hot wood to handle and most important with this method there is virtually zero springback because the part is kept hot until clamped. After clamping in place is done just rip the bag off.
This was supplied with plenty of steam from the old wood boiler I used to heat the house.

http://www.imagestation.com/picture/sraid156/p0691bc92e325110009228c7030bc6490/f553a47d.jpg

[ 03-17-2005, 07:22 AM: Message edited by: Ken Hutchins ]

[Mrleft8]

The short answer is: You need more heat. Get a "ring burner" like they use for frying turkey's and stuff. Get a 2-3 gallon pot, and make a snug fitting wooden lid, and some radiator hose. I wouldn't use PVC, but some people seem to like it just fine, if you get the schedual 40 stuff, which I gather is stiffer.

[wharfrat]

Thanks to all for your input. “Alls well that ends well”. Well, so far so good. I got the plank steamed. Taking advice, I went in search of more intense heat. And then I spotted it. In the kitchen! The large burner on the stove looked pretty impressive, so I set everything up suspended over the large element on the stove. Using the frig, chairs and what else was available to construct a scaffold to suspend the PVC tube. The kitchen table worked like a work bench for the form jig that I built that will shape the lapstrake bow section of the plank, which will hold the bend as well as the twist towards the stem.

One small problem though. The rage in my wife’s eye as she entered the construction zone expecting to enjoy a spot of Tea. Well the plank is bent, but so is my relationship. Hopefully it won’t remain as twisted as that plank. Mopping up the water from the floor must have gained some brownie points I should think.

[Bruce Hooke]

One thing to be careful about when steaming in the kitchen is that too much steam in the air can peal wallpaper right off the wall. :eek: It would take some work to do this but I know someone who did it by cooking down maple sap in the kitchen. Now there's a really good way to annoy the other user(s) of the kitchen! :D Fortunately, in the case I mentioned, it was a joint project so they could only blame themselves!

[Ed Harrow]

Originally posted by wharfrat:
...One small problem though. The rage in my wife’s eye as she entered the construction zone ...Oh I know that look - in my case it arose when she found a Norton crankcase in her oven. :eek:

As for wallpaper - that was one of my father's stories, tho in his case it was the just-papered bathroom in our house which had steam heat, and he'd forgotten to shut off the valve (the radiator was not yet installed...)

[Tom Robb]

No way that water boiled at just over 100 degrees unless you're WAY high in altitude.
Unwanted advice: stay outa the old ladies' kitchen with yer science projects. Geez!
Do the "search" thingy. There's a ton of advice on steam bending.
It's stone axe simple: lots of BTUs, (eg, a bar-b-q burner), a can of water, a hose, and a "box" of some sort.
Why all the Rube Goldberg contraptions?

[Paul Scheuer]

Tom, he's constrained to use an electric heat source.

Wharfrat, now that you have an idea of how much power it will take, you can work on a generator with less domestic impact.

My old steamer (it finally rusted out), was made using 1000 Watt dishwasher heating elements. The theory was that they were immersible , could be run dry (cherry red) without a problem, and were cheap. They also panel mount with two nuts, and have 1/4 inch "quick connect" terminals, and are 120 V.

I formed two of them into tighter circles so they would fit in a 5-gallon bucket. They are made with the element tightly packed in an insulating powder, so they can be gently bent. I didn't go much tighter than a 3 in radius.

I didn't do any elaborate switching, but I could reconnect the power to operate the elements in parallel or in series, or use only one.

You're on your own for the actual box.

Another note about steam generators - I've used mine when I needed more moisture in the air for varnishing.

[ssor]

I needed to bend a short piece of white oak and didn't have a steam chest. So I wrapped the piece in soaking wet towels and aluminum foil and put it on my bar-b-que grill for an hour, It worked just fine but the bend was only about 18 inches long.

[wharfrat]

Thanks a lot everyone it's been fun checking out all the variations of steam bending.
Hey Ed! Wow that brings back a memory long lost when I wrinkle painted the engine cylinders on my old Harley Davidson in the oven. It worked great. I decided to celebrate with a frozen Pizza, but there was something about the taste that just wasn't quite right. I still enjoy frozen Pizza today, but I never did get that taste again. It must have been the brand I suppose.