Greetings to all.
I’m new to this forum albeit I have subscribed to Fine Woodworking for some years now. I live in Galgate, a village near the city of Lancaster in England. I’ve been cabinet making for 6 years (as a hobby) and made/given away just over 100 pieces – large, small and in-between.
My preferred styles are American arts and crafts (Stickley, Mission, Greene and Greene) as well as Shaker. I’ll use any wood that I can get for nothing or nearly nothing. It’s surprising what people want to throw out. Can you believe Brazilian rosewood, teak and Cuban mahogany – all from local Victorian buildings undergoing “renovation” by builders whose idea of recycling is the skip and the bonfire.
But I digress.
Having recently retired, I decided to investigate green woodworking via a number of courses down in the woods. I started simple with a carved bowl, a hurdle (gate) and a stool. I then did a swill-making course (it’s a basket woven of oak strips) and latterly a chairmaking class. All very different from the machine-tool approach I’ve used to date.
The chair-making included quite a bit of steam bending. The tutor used a plastic soil pipe as his steam chamber; but it was a soggy affair requiring lots of ad hoc insulation and careful handling of the hot, bendy contraption. The tutor mentioned that many people use a plywood box, which provided much more insulation of itself and doesn’t go floppy.
So, I’ve built the necessary formers to bend the steamed legs, back slats and so forth but now I must build the steamer. As has become my tradition, I want to use what’s lying around, which is a half sheet of good quality 3/4 inch plywood. However, it is not marine plywood.
So (getting to my questions eventually): can anyone advice me on the best way to contruct a plywood box for steaming? It will be 8 inches on a side and 4 feet long. Steam will be supplied by a wall paper stripper I happen to have (this is what the tutor used).
* Do I need to paint the inside with something to help stop the steam de-glueing the plywood laminates? I have various oils, old paints and some weather-proof outdoor paint used for the shed.
* Should I use a lock-mitre joint to join the corners (so the edges of the ply are hidden) or is it OK to just crudely glue/screw the edges to the faces?
* What glue should I use? I have Titebond I (brown), Gorilla glue, Cascamite and white PVA at the moment.
* Is it safe/advantageous to induce a bit of pressure in the box by keeping the drain holes small (or will I blow myself up)?
Thanks in anticipation.
Replies
http://www.leevalley.com/wood/page.aspx?c=2&p=31161&cat=1,45866,45867
http://www.leevalley.com/wood/page.aspx?c=2&p=45684&cat=1,45866,45867
http://www.leevalley.com/wood/page.aspx?c=2&p=42176&cat=1,45866
Here's a couple of leads for info.
Personally I find a google search will turn up all the info I need.
I've used PVC pipe and regular plywood will work but not last as long. You can always upgrade to a better plywood later and also coat the insides with a marine spar varnish perhaps.
Edited 2/23/2006 7:51 am ET by RickL
Rick,
The Web certainly has plenty of info on it. I've spent hours parping about trying to find the gem I want in the zillion sites I seem to get when I search. Perhaps I need to learn how to search properly first - but if I try the Web for sites telling me how to do proper searching, I'll only get a million hits. (Catch 22).
So I came to an expert domain to ask and there you went and zero'd me right in. Thanks for the pointers. The LeeValley steam booklet has a plywood steam box that looks just right for me.
Lee Valley say not to use "interior grade" plywood or to paint it with anything. The steam will penetrate any finish (and the plywood) so it needs to be Good Stuff, they say. Here's hoping the plywood I have has water-tolerant glue in it. I'll find out soon enough. As you say, I can always make another box with better stuff (although I like it to be free, you know - my local timber store wants £70 for a sheet of marine ply, the rascals).
Thanks again.
You don't have to use plywood, you can use solid wood. If you scrounge up some wide 1x or 2x boards you can screw them together and your box is made.I am attaching a link to Wooden Boat Magazine. They have a forum that you can search and get lots of info on steam bending and steam boxes.http://www.woodenboat.com/And welcome to the forum too.
I think forums are ok for a guide. I don't follow any advice without documentation so that's why I gave the links. I can usually find good documented stuff on the web. I still use the old fashioned way of books and magazines for my basic research and augment it with the web. I actually get paid to surf the web for research purposes by my company.
A good old standard book that's been around for many years is Wood Bending Handbook by WC Stevens available from woodcraft.com for $14.99. I've been using it since the early 80's as a guide. For years it was one of the few published dedicated bending wood books.
Have you looked at the PVC tubes?? Caps are available so it's a quick way to go.
Actually, solid wood rather than plywood makes sense. I have some iroko of the right size and that is a durable wood so presumably will resist rot despite the steaming/drying out cycle.
The info that you both pointed me at all seems to agree that the easiest and most effective construction for a steam box is rust proof screws backed up by a thick, sticky glue such as silicone (more for steam-tightness than to stick the box together).
PVC pipe was an option, except I would have to buy it; and I wasn't too impresed with my chair course tutor's PVC pipe, which seemed over floppy when hot; and in need of insulation to avoid "weak" steam through heat loss from the pipe's surface. Perhaps he was using inferior pipe. I prefer wood to plastic anyway as it looks less....plastic.
Thyanks again for the pointers and suggestions.
Lataxe,
I was reading your post and had a few thoughts I would like to pass along. I have some projects coming up that will use steam-bent parts and am planning to build my own box soon.
I have two suggestions for material for the box, and both should be very cheap or hopefully free. The first is the PVC pipe. Your local home center or building supplier may have some pieces on hand that are slightly crushed or have cracks in them. Try to make a deal on the damaged goods. The bad sections can be cut away and still give you useable lengths of material for your steam box. Sliding the pipe into some insulated flexible duct can give you the heat retention you need.
If you can find a local countertop installer they may have offcuts or sink/stovetop cutouts of Corian or similar materials. It puts up with this type of heat well, and by joining 12" or 18" lengths together you could make a modular box that would allow you to fit the box to the project so you are not steaming a lot of empty space.
Good luck in the hunt for materials.
By the way, do you often hurt yourself when "fell walking"?
Andy
"It seemed like a good idea at the time"
Andy,
Thanks for your suggestions which will go on the growing list.
As a North American you will need a lesson in proper English. :-)
Fell - a small mountain or hill not more than 4000 feet high, covered in grass, rocks, sheep and strangely-clad walking people. Often there is wind, rain and clouds, which all flaps the trouser horribly and gets you lost. When you eventually come down, you need beer in a local pub.
Local Pub - a bar full of strange wet people trying to get wetter (on the inside) and talking all kinds of nonsense, often of an exagerated and loud kind.
Lataxe - Cumbrian name for a froe, a crude sharp instrument used to butcher logs into sticks for furniture, now replaced in most sheds by German tablesaws and other machine tools that the wife better not find out the cost of.
I once suggested making a steam box using PVC pipe, and stuffing the open end with a potato. My premise was that when the potato was blown out the bit of wood would be done. ;-) Someone actually took me seriously.
No need for glue IMHO. Let it be a bit leaky. Lots of hot steam is better than what you'll likely get in in tight box. Also, consider putting some bits across to form a rack that will hold the wood off of the bottom. Putting the box on a bit of a slant will direct the condensed water back into the boiler (assuming the inlet is at a low point.
I've seen boxes made of insulation panels, with a bunch of wood bits around the perimeter to hold it together. This particular setup was made such that it could be different lengths using a 'coupler' which was just some more of the foam applied around one end of one section. The other section would nest right into it.
Also have a friend who steamed all the frames for his boat in poly bag stock. He steamed them 'in situ' and then, when they were all loosee goosee, hauled them into place with a come-along (winch-like contraption).
You can see some pictures here: http://www.ennui.net/~timothy/Boats/EdHarrow/home.fiam.net/eeharrow/tallyho.htm
Ken's home-made ship's saw is indicative of his cleverness.
Being fundamentally lazy, I like the idea of forgetting about the glue. I'll try that.
It would be nice to somehow recirculate the hot water condensing in the box back into the boiler (a wallpaper stripper). I'll try that too (although I'll blame you if I boil myself or blow up the shed). :-)
The suggestion about a multi-part box for different size steaming jobs is a good one too. I need to steam the chair back slats at a different stage from the (much larger) legs; so I'll try that suggestion also.
As to the potato idea - this is perhaps a better concept than you realise. If the tatty is wedged firm enough and the steam box pointed at the shed wall, you can cook and mash the lovely tuber in one fell explosion. (Exploded tuber - mmmmmm)! It may also be possible to sell the splattered-up shed wall after a few shots, as conceptual art.
I like Ken's boat but he seems to have steamed it too much, as the final pic shows it to be very badly shrunk.
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