Thread: hmmmm, pallet timber WON"T steam bend?

Originally Posted by fletty

it could be either

• The $6 meat thermometer in the steamer
• the brass element cover from your Mum's (?) laundry boiler OR...
• the new shiny ratchet spanner that came with the Veritas steam bending kit?

Or, it could be the 10 digital indicators on the gloves ...

fletty

just realised its the Beasy Clamps

You mean Sue's boiler stored at her mums

Ok what steam bending kit? Ok just googled it ???? All that steel banding laying round factory creates and such and you bought that

Originally Posted by wheelinround

just realised its the Beasy Clamps

You mean Sue's boiler stored at her mums

Ok what steam bending kit? Ok just googled it ???? All that steel banding laying round factory creates and such and you bought that

....and the ratchet spanner!!

Time is running out for the pallet competition so ....I've had to resort to SCIENCE because there are no INSTRUCTIONS!

I selected a slat from a pallet and noted the marking

pallet001.jpg

I now know that IPPC = International Plant Protection Convention and...
HT = Heat Treated which is 56degC for 30 minutes (BTW, MB = methyl bromide fumigation)
This heat treatment was for the purpose of insect protection NOT changing the structure or property of the timber.
I fired up the boiler when I got home tonight, machined the slat, steamed it for an hour and bent it with the steel strap in tension. The whole idea of the strap is to stop the outside surface from going into sufficient tension to split AND to balance this against too much compression on the inner surface which displays as compression failure on the inner surface. Well, I got massive compression failure on the inner surface....

pallet002.jpg

but, it did bend, it didn't split on the outer surface and I have a bent, heat treated, pallet slat... of sorts?

pallet003.jpg

the next step is to reduce the tension on the strap or maybe remove the strap altogether and see if I can minimise the inside compression failures without splitting the outside .....I love a CAUSE!

fletty

Originally Posted by fletty

the next step is to reduce the tension on the strap or maybe remove the strap altogether and see if I can minimise the inside compression failures without splitting the outside .....I love a CAUSE!

fletty

Or two straps: inner and outer? ( Edit: on second thoughts, your former serves the purpose of an inner strap.)

I remember somebody telling me that similar results to steam bending could be achieved by immersing timber in water. I am not suggesting this entirely, but I did wonder how you would go wetting the timber before steaming (perhaps for 30 minutes). This would impregnate the timber more rapidly and the timber would not absorb your steam so readily as the moisture is already there.

Once conventional techniques are failing, I think you can adopt the radical with a clear conscience.

I have to say my only attempt at steam bending was a dismal failure as the concrete pipe, with it's 25mm thick wall, absorbed all the steam I generated. So please feel free to ignore my suggestion .

Regards
Paul

Originally Posted by Bushmiller

...I remember somebody telling me that similar results to steam bending could be achieved by immersing timber in water. I am not suggesting this entirely, but I did wonder how you would go wetting the timber before steaming (perhaps for 30 minutes). This would impregnate the timber more rapidly and the timber would not absorb your steam so readily as the moisture is already there...

Paul, while wetting helps soften the cell walls of wood, and may allow a teeny bit of sliding of cells against each other, it usually won't be enough to get it to bend successfully without heat. You can bend many woods 'green', certainly, but usually not as extremely as you can when they are heated. I think a lot of folks imagine the steam wetting the wood, but what it's really for is to heat it. Heat plasticises the wood material, which allows it to deform much more easily. It also permanently changes the material - I read somewhere, probably in Hoadley's book, that stem-bent wood is typically 40% weaker than the original material. The art in bending is to get it hot enough to take the deformation you want, but not hot enough to weaken it beyond practical usefulness. You might improve your success rate by soaking the wood til it is thoroughly wetted (which would take substantially longer than 30 minutes, I think). I've read somewhere that adding a bit of detergent to your soaking & steaming water helps.

I think one of the main advantages of thorough soaking would be to increase the rate at which the wood heats up in the steam box. Wet wood is a much better conductor of heat than dry wood. From my own limited experiences of wood-bending, it takes much longer than you think to heat even a skinny bit of wood right through.

Fletty, my lad, you are betting on on a hiding to nothing, trying to bend unknown woods! There are many woods that simply will not bend, no matter how you cook 'em.......

I admire your stubborn tenacity!
Cheers

Its nice to see you are still doing your Pallates

Originally Posted by IanW

I think one of the main advantages of thorough soaking would be to increase the rate at which the wood heats up in the steam box. Wet wood is a much better conductor of heat than dry wood. From my own limited experiences of wood-bending, it takes much longer than you think to heat even a skinny bit of wood right through.

Ian

I admit I don't fully appreciate the physics of steam bending, but I was advocating the use of water as well as heat: Not instead of. I think you may well have a point in the problem of getting the heat into the timber in the first place.

This would be down to the capability of your steam generator and the ability to retain the heat.

Just a charlatan's thoughts.

Perhaps I should make up a pallet out of spotted gum, send it to Fletty and then he would be right! Actually I did supply some spotted gum to a pallet manufacturer once, but they had to increase the air pressure for their nail guns as it was too hard for their normal settings! SG is one of the good bending timbers .

Regards
Paul

Originally Posted by Bushmiller

Perhaps I should make up a pallet out of spotted gum, send it to Fletty and then he would be right!

Regards
Paul

ooooh, you are wicked .....but I like it!

Fletty

Hi Fletty
I only opened this thread because I wanted to see how YOU would build a crossbow.

What a disappointment.

As I continued to read.......I was shocked to find that you DON'T own a moisture meter? and you have so many other interesting toys/tools.

Have you given up on your pallet timber bending folly yet?
Your persistence is admirable but........

Just make a square box out of the pallet. Add a raised panel if you want.

Then get some Spotted Gum from Paul and steam bend to your hearts content......and buy a moisture meter.
Maybe a crossbow could be your first project?

Scally

One of the definitive books on the crossbow is the book "The Crossbow" by Sir Ralph Payne-Gallwey.

It covers everything the average backyard bowman could wish for as well as a section on catapults and trebuchets, which is so handy if you have an annoying or pesky neighbour.

Ralphy (pictured below) died in 1916, but his book is still available through Amazon, which is where I got mine. A very interesting read even if you are not planning (immediately) to take somebody out.

Ralphy.jpg

I will be sending Fletty the spotty pallet as soon as I can get in touch with Doctor Who to fit it into a 5Kg Aussie Post bag.

Regards
Paul

Originally Posted by Scally

Have you given up on your pallet timber bending folly yet?
Your persistence is admirable but........

Hey Scally, it's been a long time between gallery openings!
Alright, I confess, I've been trying to steam bend DRUMS to compete!
I was going to send you off on a wild goose chase with some cock-and -bull yarn about furniture but NO .... It' drums, Drums, DRUMS!
Yes, of course I have a moisture meter, my tongue can pick a dry red from 10 metres!
see you on the weekend mate?
fletty

Hi Paul,
That fabulous book cover reminds me. My sister is travelling soon by train from Scotland to London on the Caledonian Sleeper. In this age of political correctness, she was reduced to hysterics when she read that, on THAT train, you can travel with your dog and SHOTGUN!
She asked if the shotgun was compulsory because she was currently shotgun deprived?
ya gotta love this World!

fletty

Fetty

That picture is actually a caricature that was published in Vanity Fair. This is the book cover:

Rallphy's The Crossbow.jpg

Still, at least we know how to travel in Scotland now and the necessary apparel .

This is a link to the book itself for any pirates and mercenaries out there:

https://glow420.files.wordpress.com/...lloway-ocr.pdf

All the best for the pallet. I hope people won't misunderstand if you tell them you are going on a bender over the weekend.

Regards
Paul

You guys are so helpful

But I really don't need any help finding more interesting projects!!

I have some instructions and some funny videos about making Trebuchets. (All my neighbours are on the list!!)

I know a guy who makes a few drums. I have even invested in a Nova lathe to replace my home-built Router lathe. Mostly I let the Africans chop out the drum shells.

A mate of mine just built this Atabaque. His father has a strange affliction with trying new projects too.
They cut the staves.....glued, nailed and strapped the bottom s of the staves together first. Then they used a variety of methods to steam the rest of the staves while using ropes to wrestle them together.
I think he tried a few methods before he had success.

Looking forward to seeing you at the Show tomorrow.

Cheers