Tigging aluminum heads

[hotnsexxy454]

I am looking for info regarding welding process for aluminum engine heads. I have Synchrowave 185SD using 4043 aluminum filler rods. Have heater to bring heads up to proper temp. Any info, videoes or books, or other recources would be greatly appreciated. Thanks!
F. Scott
ShadeTree MotorSports
100 CR 2181 E
Cleveland, Tx 77327

[fun4now]

drill

drill the ends of the crack befor you start the repair.clean clean and clean agin. (not with your wire brush you use on steel)thouse are the simple basics in shoure there are fare better welders out there that will give you some tricks to tame the beast.
good luck and happy welding

[fun4now]

V the crack

its also good to V out the crack if you can.defenetly drill the ends to stop the crack.a nice V will help you get a good bead all the way through, build it up in multiple passes if need be. sorry i cant help you with what filler as i have never tig'ed.cleaning the oil out is verry verry important as the cast alum. will trap in the oil and trash you're weld.if you have a plaiting shop (zink,crome,nickel,oxcide) im shoure they would vaper clean it cheap 4 you.
hope all comes out well.
P.S> if you can wait a little bit im shoure HAWLK or andy will tell you what filler to use as they are the prows.

[ASKANDY]

Heads can be difficult. Is it a stock alum head or aftermarket race head. Either case will need 5356 filler or depending on where the repair is made, a 356 filler can be used. Stay away from the 4043. It doesn't have the strength needed. You 180SD might be a bit small for this type of work but you may get by with preheating. You will find that stock heads are a pain to weld because of the poor casting quality. The oil will bake out as you weld and you need to stop and clean quite often. Even with some aftermarket race heads, cleaning is the key. You will also have to upgrade to a better tungsten like a Zirconiated. It will handle the heat better than a Pure or 2%.
Also, pull the valve seats and guides out if the repair is near them.

Good luck

Andy

[HAWK]

hotn***xy454,

Welcome aboard. I don't think there's much to add as the guys and Andy have you well informed. The only thing I'd like to say is do make the effort to get some 3/32" zirconiated tungsten as Andy suggested. It is awesome for high heat applications with a standard squarewave machine like the Syncro 180. It will ball on its own so the DCRP and copper technique is not really necessary.

As FUN4NOW mentioned "v-ing" the crack is a great suggestion. If possible us a carbide grinding burr on a die grinder. This should eliminate the contamination caused by using a regular grinding wheel on an angle grinder.

Do clean your filler rod with Scotch-Brite and acetone just before welding. I know it sounds like overkill. You are going to need all the help you can get to make the filler lay in good.

A good preheat will be critical to your application. It will certainly add heat to the weld area to help out when the Syncro 180 tops out. The other big thing it will do is boil out the oil and other casting impurites. Try to stay under 350 degrees farenheit as this is a premium interpass temperature if you need to make multiple passes. If you can use a thermal blanket to help hold the heat in the head you will have a better chance of getting the filler to take. The head will act as a huge heat sink. Good luck and keep us informed.

[imported_Blackplague]

I don't know if the 180 will get thru it.

If you don't have to weld too much you can probably do it with preheat. The problem with aluminum heads like Hawk pointed out is they are a real big heat sink, they dissipate the heat almost as fast as you put it in. You'll probably be able to do small cracks, but if it gets into something big, like deck work or putting back a combustion chamber you may have a hard time.

Like Andy said, Aftermarket heads are real easy to weld, where stockers {depending on the alloy} can be a little more challenging.

Becareful with the preheat. If you get them too hot, you'll start loosing the heat treat from an aftermarket head.

Zirc tungsten will be a must with the amperage you'll be running.

[paulrbrown]

hotn***y, using a gas which contains Helium along with argon will give you a little more heat also. A 50/50 mix should work pretty well, you never said if the heads were cracked or you are just building up areas. Good luck, Paul

[HAWK]

I run a lot of 75%helium/25%argon with the Dynasty 200DX and have pushed some very large heat sinking weldments well beyond the reasonable limits. The 180SD will start fine with this mix if you can find it. Stay away from 100% helium as the arc start is quite rough and somewhat erratic. It takes some practice to weld well with pure helium. Just the 25% addition of argon is night and day on ease of use!

[HAWK]

As blackplague pointed out: Re: I don't know if the 180 will get thru it.

I too wonder. I think you have some great advice. Let us know what happens.