How are you guys welding stainless V band clamps to truck manifolds? What rod are you using? Preheat the manifolds and cool in sand? Tig? Stick?

 

The manifolds are cast iron, so i would say Stick, but that is going to be a bitch and the rods are $$$$$. I have has some success with using a Mig welder at 200 amps and mild steel wire. And as far as i know it is still holding.

 

ive personally had good experience welding mild steel to cast with a flux core welder..turned the heat up, cleaned up a good ground and its held for 3+ years

 

Nickel rod with the stick welder? All the pics I've seen here look like tig. I've had a bitch of a time getting cast iron to stick to anything, it takes a lot of prep and prayers.

 

I had some welding done to cast iron heads by a pro. He heated the heads up in an oven before doing the welding.

 

i would spend some time on this, preheat the manifolds first, if you dont, and it cracks, have fun.

mine were tig welded, and look absolutley amazing, he spent 6 hours welding them and he said hey used a special rod. lots of preheating and post heating, he welds cast to mild for living so, i know theyll be fine.

 

I think these manifolds have a lot of steel in them because they seem to take to welding pretty well. A test you can do is to hit them with a grinding wheel. The longer the sparks it throws, the more steel there is in them. If I was going to try and do this, I would clean and prep the cast well and preheat to a few hundred degrees just to relieve stress. I would then use 309 SS tig rod which is designed to weld dissimilar metals. After welding, I'd "peen" (tap lightly) the area with a small ball peen hammer to relive stress. Then allow to cool as slowly as possible. That should get the job done.

 

Ill prob try this method, and let them cool in an oven, reducing the temp every hour or so.

 

mine are map tig welded stanless flanges and filler. they were preheated and welded inside and out.

 

What is "map tig welded"?

 

IMO still not a good idea for longevity to use just a weld as a union between cast and mild/SS when it will be supporting weight and have a ton of heat cycles

look into doing something like this if you still want the connivence and leak freeness of a V-band and still have good integrity


atleast what i did





In this way the studs still support the actual union not the weld....... I first tightened the nuts and then tacked the nut and stud from the back so they can not loosen

I then put down a small SS TIG bead between the mild steel flange and the cast manifold flange for sealing purposes only, as the studs are providing the strength of the union

so it is a one piece unit and all

works great

 

I would agree with you ... I welded some SS wastegate flanges to a couple of GTP manifolds and not only did the welds come out great, but I had zero problems. Used a shop Millermatic MIG welder. The key was in the technique of the welder and keeping the iron quite hot. We did not use preheat, but did allow it to cool in some kitty litter. Very, very easy to do.....

 

this sounds like it would come out very nicely and work very well

 

to do it "right" you need to pre heat the cast iron to 300* (don't let the wife know you are using the oven!), Tig or stick weld them with a 55% nickle rod, and then put them back in to oven so that the whole thing is at an even 300* (weld and manifold), then shut the oven off and let it all cool down slowly. The oven will hold the heat longer and aloww it to cool at the same rate. The reason you get cracking is that the cast iron and what ever you weld to it, and the weld all cool at different rates. They also shrink at different rates and that causes the crack. The high nickle content rod makes a softer more flexible joint that will allow for the slight movement variations. Just my $.02

 

I did some for a Buick GS with a turbo LQ9 and they turned out great. I cut the manifolds back as far as I could for space, preheated them in the oven as hot as it would go, "buttered" the end of the manifolds with nickel rod, then welded the stainless Vbands to the manifolds with 309 rod. I did a test piece with a chunk of what I cut off the manifold and welded it to a piece of 304 tubing. Then I beat the **** out of it with my biggest hammer and it lived with no cracks. Car has probably 5k miles on it with no problems.

 

Great advice from everybody on here. Didnt read anything that i would disagree on. me personally, i heat the cast and then weld with just flux cored mig and let it slowly cool down naturally. no problems at all

 

Here is the passenger side.

 

My Malibu has been good for 2 years now. I welded schedule 40 pipe fittings to a pair of truck manifolds.

"V'd" all pieces, preheated with an oxy-acetylene torch, mig welded, than post heated with torch.

 

Wow, great help everyone! I'm going to cut the ends off the manifolds and try to tig some some scrap mild steel tubing to them. I don't have an oven at my shop so I preheat with a torch and use a steel box packed with sand to cool slowly.

 

ive welded mild steel to a cast iron manifold with my lincoln flux core welder ( with a 75/25 mix added) its held up just fine , i didnt preheat or ping it ......and i would do it again with no worries.i do have some pics also .