What glue for steel to copper thats good for Diesel

[bert]

Normally I would take this job home and tig this together but I need it back in the fuel tank this weekend so I can bleed the fuel system.

This is what broke a few weekends ago on my boat, I've got the new fitting and drilled it out to fit the 10mm copper pipe inside it. I tried to solder it but with no success last night.

What glue would permanently stick copper to steel and be happy living in the top of the diesel tank?

Thanks

 

[grim_d]

An epoxy.

 

[Kram]

If you could get it down here, Id do it with silverflo55.
Solder should work, it needs to be spotlessly clean. Do not heat the joint directly, heat either end. Plenty of flux. Wrap a ring lf solder around the joint.
A short dip in hot citric before and after too.

If the copper is long or thick wall, wrap the far end in fibreglass or similar to keep the heat in.

 

[JMS1972]

If you could get it down here, Id do it with silverflo55.
Solder should work, it needs to be spotlessly clean. Do not heat the joint directly, heat either end. Plenty of flux. Wrap a ring lf solder around the joint.
A short dip in hot citric before and after too.

If the copper is long or thick wall, wrap the far end in fibreglass or similar to keep the heat in.

Beat me to it. Definitely a silver solder job.

Should be easy enough with a plumber's size torch or even a big chefs torch if you can keep the heat near the joint. Celcon blocks or similar ....

 

[outofthefire]

Is the steel zinc coated, if it is that won't help with the soldering

 

[Brad93]

Braze or Solder. I wouldn't trust glue

 

[Agroshield]

Solder should work, it needs to be spotlessly clean.

As he has already tried to soft solder it, silver soldering will be difficult unless all the soft solder is removed.

Before suggesting an alternative process, perhaps we should try to understand why the original one has not succeeded, especially as it is a situation where soft solder would be first choice. It is either not enough heat, not enough cleanliness or an unsuitable flux.

Braze or Solder. I wouldn't trust glue

Best not to fly on a modern airplane then as the wings are glued together. Or drive a modern car as the panels are glued together. Stick to your Sopwith Camel (whose fabric was also glued on).

 

[grim_d]

Best not to fly on a modern airplane then as the wings are glued together. Or drive a modern car as the panels are glued together. Stick to your Sopwith Camel (whose fabric was also glued on).

Came to say the same thing! Its wild how much of a commercial aircraft is glued together

 

[Seadog]

Soft soldering should have worked. A flux such as Baker's Fluid would be best with steel. Cleanliness is essential. Heat the bolt and let the heat soak through to the copper.

 

[bert]

I'll try again, the copper is old bit cleaned to bright with paper and wiped clean with kitchen roll

Bolt is plated but I sanded back to steel at the end and it's drilled out inside so still plated on the threads

Flux is a gosystem water soluble flux and the matching solid wire solder. Bought from b&q

I'm definitely a novice at soldering pipes and the solder just ran off onto the floor and didn't flow out even when trying to gently heat it.

 

[bert]

It would appear my last attempt has managed to stick the two parts together, heated the pipe and the bolt and let the heated parts melt the solder

Thank you all for the advice on that. As an emergency solution would a 2 part epoxy glue be suitable as I can keep that on the boat.

 

[Kram]

As he has already tried to soft solder it, silver soldering will be difficult unless all the soft solder is removed.

Soft is luckily, soft. An easy task to clean it off pipe and out of a hole.

@bert Some epoxies may do as a temp repair, but some will degrade, perhaps not soon but, long term epoxy is not great for fuel resistance.
Id prefer to keep a can of mapp and some silverflo rods.

 

[grim_d]

Epoxy has excellent diesel resistance.

 

[Brad93]

I'm not denying that things are structurally glued. But I can assure you that the proper solution is not to glue it.

You've always got to be so cynical @Agroshield. I'd love to see you post some of your work, you always have an answer for everything so it appears you must work in 100 different top flight industries...

 

[Maker]

I'm not denying that things are structurally glued. But I can assure you that the proper solution is not to glue it.

Exactly, glue has it's place and a fuel tank isn't it.

 

[Bullet2012]

I'm not denying that things are structurally glued. But I can assure you that the proper solution is not to glue it.

You've always got to be so cynical @Agroshield. I'd love to see you post some of your work, you always have an answer for everything so it appears you must work in 100 different top flight industries...

Exactly, glue has it's place and a fuel tank isn't it.

But Google says

 

[Kram]

Epoxy has excellent diesel resistance.

Some do, yes, and there are fuel tank coatings designed for permenent submersion, but, I wouldnt trust a generic one. Epoxies are a large range of chemicals with many different types.

 

[Brad93]

I'm the first one to suggest not welding something if there is a cold solution.

Rivets, quite often far superior to welding. No distortion. Guaranteed mechanical properties. I suggested this to someone just the other day for some intercooler ducting on his track toy.

Belzona/Devcon etc. industry driven solution for wear, poor fit up, cracks, pitting and a variety of other problems. Again a cold process.

Modern adhesives are fantastic things, I'd happily glue aluminium sheets and all sorts of dissimilar materials together. Providing the adhesive is the correct one for the job.

But some things are time tested, and soldering that joint is one of them. And as proven by the OP, it has worked nicely.

 

[Brad93]

Some do, yes, and there are fuel tank coatings designed for permenent submersion, but, I wouldnt trust a generic one. Epoxies are a large range of chemicals with many different types.

Exactly this

The Loctite range is a whole catalogue in itself.

 

[mike os]

I'm not denying that things are structurally glued. But I can assure you that the proper solution is not to glue it.

You've always got to be so cynical @Agroshield. I'd love to see you post some of your work, you always have an answer for everything so it appears you must work in 100 different top flight industries...

I’m sure airbus buy their glues off eBay… says poxy on the tin innit … good enuff mate…

Sometimes it’s just not worth the effort @Brad93