using wood for a backing plate instead of copper?

[MrKrink]

has anyone tried using wood instead of copper when welding?
i was about to start on my project and was thinking wood could easily be shaped and formed to put in the receiver. and i got alot of wood.

[smoggle]

Wood will burn when you weld. You want something to backup the weld to reduce the amount of finish grinding of the welds after the work.

[kmw]

The "Eastwood Company", an automotive restoration specialty tool shop, carries a set of easily formed copper "shapes" for welding. Do a search for them, they have a nice online catalog. Their tools aren't the cheapest, but they carry some interesting items. Powder coating anyone?

Disclaimer -- I have no financial interest in Eastwood (though I think they have a financial interest in me!), I've just used a lot of their tools and supplies keeping old British sports/racing cars running.

[weasel]

Wood while it is burning will contaminate your weld. You also want your weld to flatten out on the back side. Use brass as a backer, the steel won't stick to it. LOL

[Dr. Fixit]

1/8" or thinner copper sheet can be ordered from http://www.mcmaster.com and it is pretty cheap.

[mgfun]

You will also benefit from using copper, or to a lesser extent, brass, in having a high thermal coefficient material in contact at the weld si=te to pull excess heat away from the weld quickly. This limits the size of the heat affected zone and the area where the heat treat is impacted.

[Karbinator]

Buy 6" pipe form lowes, and pound it Flat..... less than a buck, and you can have it tonight.
I feel it's shaped faster than wood, and yes...the wood will cause contamination. Don't do this.

[TOM R]

good idea carb, i bersonaly got small copper/brass bar from a local steel supply

[Brass Scrounger]

Hit your local scrap yard. There will be someting there you can use. And the cost will be a fraction of what it would cost new.

[Pirate]

Buy some copper sweat couplings in 1" or bigger at Home depot. split them and you can
flatten them out or easily bend to shape to fit inside

[big steve]

wood wont work!

[gordie k]

if you use wood it must be a very hard wood but it will add carbon debending which type you use
that was an old trick for weding keys on cranks and shafts the wood onley protected the good side so contamation was not a promblem but when you tried to mechine a new key it could be as hard as 60r now all you could is grind if it was still hard at finish it would brake out and you had junk copper is best
the thicker it is the better

[EZFEED]

Copper buss bar from an electrical supply.

[toomanymachines]

I think that the only thing that you would get from wood is a bunch of smoke.. it will just make welding very difficult. you eyes and lungs will appreciate that you do not use it.

[justashooter]

don't let these guys piss on your parade. not a welder among 'em.

as an old salt in the puddle, i can say that i have welded with oak as a backup when nothing else was handy. it does smoke a bit, but won't contaminate your weld badly. welds with a wood backup will not be 65 rockwell. carbon is not all carbon. welding chemistry is more complicated than that.

that being said, use copper. brass contains tin, which will contaminate your weld, but only on the surface.

copper is best because it sinks heat so fast that it will not puddle when in contact with steel in the liquidus range. keep it that hot for long, and it will. the zinc in tin is not so forgiving, and will vaporize into your steel puddle, but float on the surface before the puddle solidifies.

[smoggle]

We are just saying it's not good. Just saying that you can get a much better backing very cheap and easily. Dense wood is great for a backer but there are much better things available and they are common and easy to come by.

[MrKrink]

thanx guys, i didnt think about flattening copper from home depot, good idea. home depot is just down the road.

[88comm]

On inside corners that are rounded I used copper sheeting (Roofing contractor trimmings) backed up with some round steel rod, then held with a "C" clamp. All that metal worked as a heat sink, and it saved internal grinding with a die grinder.

What are your thoughts on a light spray of "anti spatter" on the copper before its installation? Its used by welders to keep weld spatter from sticking to the work. Will it contaminate the weld?

[js412000]

I never use anti-spatter. It does not work as advertised, so why bother?

[justashooter]

anti spatter is used to reduce clean-up time in industry. it works as advertised, and if sprayed in mig nozzles will make them easy to clean, as well. flux core and dual sheild wires need this less than solid mig wire because the spatter droplets are smaller with tubular wires and solidify before they contact your workpeice. deposition rate is also better with tubular wires - something like 85% versus 65%.

too much anti spatter on your weld preparation will cause turbulent gasses in the weld puddle if your advance is rapid, so use judiciously.