Welded Wooden Step Stool

Very interesting..Nice job.

-- Rob (A) Waxahachie,TX

Fascinating…

“At the very high temperatures attained by mechanical friction (higher than 180°C) the characteristics of the wood lignin and hemicellulose between the wood cell walls change, and start to flow, hence the initial phase of « melting ». The wood fibres released by this flow of materials become then entangled, and form a high density composite by being drowned in the molten material once this has cooled down. This composite constitute the bondline, or better the weldline of the timber joint. The researchers involved have also clarified some of the main chemical reactions occurring during welding. The mechanical resistance of the joints formed by welding in 2-4 seconds is comparable to what obtainable 24 hours after gluing.”

“The second process developed is high-speed rotation welding of dowels. A dowel in rapid rotation inserted by mean of a simple electric drill into a substrate welds to the substrate with a mechanical resistance 20 times greater than the traditional hammer inserted dowels, and with a strength comparable to dowels glued-in for 24 hours with PVA adhesive, all this without the use of an adhesive.”

-- I am always doing that which I can not do, in order that I may learn how to do it. - Pablo Picasso

I can’t wait to see this video.
It sounds fascinating!!
the stool is beautiful – a lovely addition to a kitchen.

-- ~ Debbie, Canada (http://www.execulink.com/~yohan)

now that is cool. who’d thought to do that. Back in boy scouts you learned that if you rub wood together you get fire, not glue. I suspect different woods, higher oil content, moisture, and such would have different welding characteristics and techniques.

thanks for sharing, pretty interesting.

Yes very interesting! I’ll have to look into that process, I’ve never heard of that. I love learning something new!

-- http://theinquisitivewoodworker.com/

I love Google :).

Wood Welding

-- http://theinquisitivewoodworker.com/

Most interesting. Thanks for bring this method of joinery to our attention.

Best wishes.

-- CanuckDon "I just love small wooden boxes!" http://www.hilsbiblechurch.org/

When I was searching glueless joinery, I came up on wood welding, but just kept on going. I’m glad you stopped to take a look around. Nice project!

-- You can discover more about a person in an hour of play than in a year of conversation. (Plato)

I guess we can’t pull the old trick of sending someone to go get the wood welder anymore. fascinating story and nice step stool for your niece. thanks for the link

-- Joel Tille

Cool stool Leon! Interesting joinery method as Don says.

Thank you Mike for the article.

-- Carpe Lignum - Seize The Wood,

Didn’t get around to making my video this weekend. Something about plumbing. Hopefully soon.

As I was thinking about the video, I started asking myself why would you want to use wood welding when you could just glue things to together like you always have. All the joints I welded together could have been glued. I only used wood welding for this project because of the contest. The contest is also the only reason I learned about wood welding.

As I thought about it, It occured to me that this step stool is pretty complex with 28 joints. The glue up could have been quite complex and could easily have used more clamps than I have ( “you can never have too many clamps” ). If I don’t have enough clamps then I glue it up in assemblies and then glue those assemblies together. Lots of time waiting on glue to dry. Even with enough clamps this would have been tricky to get everything in place and clamped ( by myself ).

With the wood welding, I only used two clamps. There is no waiting for glue to dry. As soon as a joint was welded, I could move to the next.

Now that I think about it, I might just use wood welding on a future project.

-- Leon -- Houston, TX - " I create all my own designs and it looks like it "

Leon:

I’m interested in your wood welding. If you attach two pieces together as a joint is the connector piece (Dowell) spun through both pieces of wood?

-- What happens in the workshop stays in the workshop. No wait that doesn't sound right. Karson Southern Delaware karson_morrison@bigfoot.com †

Yes. I drilled a 5/16” hole through the top piece into or through the second piece. I then chucked 3/8” dowel into my drill. Then pressed and spun the dowel through both pieces.

I never found any information on the Internet on how to do this so the following is the technique I developed

The pieces to be joined need to be well secured with clamps to something solid ( bench, table, etc) ( You need to apply a lot of pressure and you don’t want it moving around )
I used a corded 7amp 1/2” drill. ( Need lots of speed and horsepower and don’t think a battery drill would work in the long run )
I beveled the leading edge of the dowel to help it find the 5/16” hole
I bottomed out the dowel in the chuck ( you need to apply a lot of pressure and I didn’t want it to slip)
I used a keyed chuck so I could really tighten it ( didn’t want it to spin out and I don’t think a keyless chuck would work)
I align the dowel with the hole and get the drill up to full speed before I start pressing
Once I start pressing, I don’t stop until I hit bottom
As soon as I hit bottom I stop spinning and pressing but I leave the drill/dowel in place ( the process needs 3-4 seconds to cool and solidify the joint )
I use the key to open the chuck and release the drill so I can remove the drill
I then cut the dowel off using a flush cutting saw

Hopefully I can find time to do the video. If a picture is worth a thousand words, what is a video worth?

BTW – It does smell like it’s burning when you are inserting the dowel but so far no flames

-- Leon -- Houston, TX - " I create all my own designs and it looks like it "

Interesting concept. I may have to give it “spin” on a project also.

Very cool! I’ll have to check into that – I’m a fan of “no nail / no screw” projects.

-- Tim D. - Woodstock, GA

A very novel method of joinary and very nicely explained. I am very eager to use it . Awaiting the video but what you have said is more than enough.
Sharad

-- patanjali