Utilizing Silicone-Bronze filler
 

Sometime soon I'll hopefully be starting my own manifold, I've done a few others but nothing terribly complicated. I'm planning on going with stainless for obvious durability reasons, as well as a fairly thick flange, and was wondering if I could use some Silicone-Bronze filler to help avoid distortion in the flange.

Also I was going to go for a more ram-horn or long tube manifold, as opposed to the mini-ram/log kind of deals I've done in the past.

I'm going to have it bolted down as well but I was wondering if it would be worth the extra measure. The only thing that concerned me was that the strength of the actual bead is slightly reduced, which I could make up for with a bit more heat and less filler, but that kind of cancels the point of using it at all.

I just wanted to hear what some experienced welders/ fabricators would say.

Re: Utilizing Silicone-Bronze filler
 

i think it is like 80% strength but im not sure that is true at exhaust temps as well

Re: Utilizing Silicone-Bronze filler
 

I know its more flexible at heat than SS filler, whether thats good or bad is the question.

Re: Utilizing Silicone-Bronze filler
 

well when i tigged it, it seems like a was barely even on the peddle enough to even get the steel molten. it just kinda sucked in there and i smoothed it out with the arc. really weird to go from mild to try something like that.

Re: Utilizing Silicone-Bronze filler
 

When silicon brazing you dont wanna make a molten puddle. You want to get the base metal only hot enough to melt the brass since the melting point it about 1000 degrees cooler. Its not supposed to be a fusion welding process.

Re: Utilizing Silicone-Bronze filler
 

?

I'm talking about using Silica-Bronze filler for Stainless.

Re: Utilizing Silicone-Bronze filler
 

same thing

Re: Utilizing Silicone-Bronze filler
 

I've done it before, I didn't have to braze or preheat anything?

Care to elaborate?

Re: Utilizing Silicone-Bronze filler
 

how are you doing this? torch, tig, heat gun set to nog?

Re: Utilizing Silicone-Bronze filler
 

I got a little Miller 200 tig, but my friend has a torch as well. I didn't think it needed preheating, just use the Bronze filler in place of the standard SS.

Re: Utilizing Silicone-Bronze filler
 

Now it has been a few years since I have used Silicone-Bronze filler, but iirc, it is good for cast to mild or ss, but not in your app. The two reasons why are heat and vibration. Now even at room temp, it has a fair bit less strength, but heat it up and it is even worse. It also does not like to be vibrated so on an engine is exactly where it was not designed to be. It does flow quite nice and is good for repairing cracks, and on thin sheet, but I wouldn't use it in this case.

I personally would just use a high nickel rod, and pre to 500F, keep it warm well welding and post heat let it cool slowly in sand or heating blankets. As for the actual rod Ni33 and Ni99 I have used both, but can be both pricey and hard to come by. Most often I use SS E309 as it is easy to find and relatively cheap, it also has a high Ni and Cr components.

In reality I would probably just go down to your local welding supply place, and ask what they have in stock, and how much. SS E309, is good stuff to have around anyway as it is a good all purpose SS rod, as well it is what you use to join mild and SS.