Cast Iron Repair - Best Epoxy?

[Patrick Walsh]

Hmm this Belzona stuff has my interest. I have a cast aluminum shaper fence dust port that’s gonna need a repair. Sounds like if I want the best fix this stuff is it. Is there a specific formulation geared toward aluminum and or should I just call the manufacturer.

[Brice Rogers]

Silver solder is incredibly strong. Probably stronger than the cast iron. But you need to get the cast iron quite hot. It works best for very narrow gaps and flows like water. I'm not sure if it is the best choice for this application, but it is REALLY strong. I use it to silver solder (45% silver) broken bandsaw blades and have never had one fail at the solder joint.

[Rob Luter]

I'll second (or third) the silver solder suggestion. Brazing with brass would work too. Almost any tool and die shop should be able to do this.

[Tom M King]

Hmm this Belzona stuff has my interest. I have a cast aluminum shaper fence dust port that’s gonna need a repair. Sounds like if I want the best fix this stuff is it. Is there a specific formulation geared toward aluminum and or should I just call the manufacturer.

JB Weld Marine would be fine with that repair.
https://www.jbweld.com/product/marineweld-twin-tube

[Patrick Walsh]

I figured so much Tom. It’s a crack in the same exact place in the same exact machine as Joe Calhoon did on his T23 with JB weld. You know me I’m the king of overkill. God forbid that port should ever crack enough to warrant it non functional. I’d have a freaking egg.

JB Weld Marine would be fine with that repair.
https://www.jbweld.com/product/marineweld-twin-tube

[Tom M King]

Judging by the prices I found on Belonza stuff, the difference in price between it, and the JB, would be a bit more than 100 bucks. As I've said earlier, in this thread, I've never had any such epoxy repair fail, and that doesn't seem like an unusually high stressed piece.

edited to add: If you wanted to do a pretty repair, which I expect you do, the 3M duo cartridges using a gun, and mixing nozzle will allow you to run a very small bead right where you want it. Both the plastic nose on one of my tractors, and one of the back fenders on my dually have been held together with DP100 for 8, or 10 years now, and you have to look really closely to see that there is even a crack. I even have a long term fix still holding on a plastic fuel tank, on a generator, with that same stuff.

I'm not sure which one is right for aluminum. There are quite a lot of different ones.

If you go the duotube route, the best prices I found on guns and nozzles, back when I was looking for one, came from Golfworks, for both the gun, and nozzles. The Golfworks gun works just fine. https://www.golfworks.com/the-golfwo...ge-gun/p/esg2/ Poke around on their site, and order some mixing nozzles in the same order.

The review that says it only fits their brand of cartridges is not correct. It does indeed fit the little 3M duotubes.

[Richard Coers]

Silver solder is incredibly strong. Probably stronger than the cast iron. But you need to get the cast iron quite hot. It works best for very narrow gaps and flows like water. I'm not sure if it is the best choice for this application, but it is REALLY strong. I use it to silver solder (45% silver) broken bandsaw blades and have never had one fail at the solder joint.

Silver soldering a carbon steel bandsaw blade and a grey iron casting are wildly different animals. The graphite in the cast iron will likely not play well with the soldering process. Depends on the alloy of course.

[Patrick Walsh]

Tom

Good news. I have one of those guns and the tips. I use a them for a project I use to glue the joints of fiberglass gutters.

I also use a product sold for gluing Azek or pvc trim boards.

https://fibergutter.com/installation/

http://www.pvctrimwelder.com/pvctrim...cartridge.aspx

Couldn’t find the gun but it’s the same for the small tubes in the bottom link.

Sweet product the gutters themself if your not familur.

Core era get mitered and joints are laid up from the inside with fiberglass sheets. Been I staling them for a number of years now and have had zero failures. I even put them on my own house. I can hang of them and bounce up and down as hard as I can right at a joint and no issues.

$17lf though last I used them.

Judging by the prices I found on Belonza stuff, the difference in price between it, and the JB, would be a bit more than 100 bucks. As I've said earlier, in this thread, I've never had any such epoxy repair fail, and that doesn't seem like an unusually high stressed piece.

edited to add: If you wanted to do a pretty repair, which I expect you do, the 3M duo cartridges using a gun, and mixing nozzle will allow you to run a very small bead right where you want it. Both the plastic nose on one of my tractors, and one of the back fenders on my dually have been held together with DP100 for 8, or 10 years now, and you have to look really closely to see that there is even a crack. I even have a long term fix still holding on a plastic fuel tank, on a generator, with that same stuff.

I'm not sure which one is right for aluminum. There are quite a lot of different ones.

If you go the duotube route, the best prices I found on guns and nozzles, back when I was looking for one, came from Golfworks, for both the gun, and nozzles. The Golfworks gun works just fine. https://www.golfworks.com/the-golfwo...ge-gun/p/esg2/ Poke around on their site, and order some mixing nozzles in the same order.

The review that says it only fits their brand of cartridges is not correct. It does indeed fit the little 3M duotubes.

[Tom M King]

I'm sure they're nice, but I have nowhere to use plastic on the old houses I work on. Most of them don't even have gutters, but this one needed them, so we used these. They come in special shipping boxes that you can walk on, and every piece separated in the boxes by specially designed dividers, and foam sheets.
https://classicgutters.com/

I put them on this house.

[Patrick Walsh]

Tom,

I wanted to do copper built in gutters but the cost was crazy. I think like 50-60k. Copper half rounds I was discouraged from by the copper guy I used to work with.

Being my home a bungalow the only right thing to do was replace the original wooden gutters. I had replaced a few runs over the years and honestly in less than ten years the new growth timber would rot even keeping them oiled.

The fiberglass gutters I used are actually made using actual wood gutters. In person you can’t tell the difference as the grain is also cat into them.

Not historic but pretty darn nice.

Again I wanted copper but even the half rounds fully soldered “not the kind with fittings for joints and corners” where like $33lf I think. I’ll throw lead coated down spouted in to match my valleys drip edge and chimneys lead coat through pan and be happy.
‘

I'm sure they're nice, but I have nowhere to use plastic on the old houses I work on. Most of them don't even have gutters, but this one needed them, so we used these. They come in special shipping boxes that you can walk on, and every piece separated in the boxes by specially designed dividers, and foam sheets.
https://classicgutters.com/

I put them on this house.

[Tom M King]

Those weren't copper, since they wanted them to be white. They were about 5200 for the materials. I forget what the copper was, but it was multiple times that, and wouldn't have looked right anyway.

[Patrick Walsh]

I didn’t think they were copper they are white.

They just reminded me of the copper half rounds that’s I am used to working with..

Nice windows on that house..

Those weren't copper, since they wanted them to be white. They were about 5200 for the materials. I forget what the copper was, but it was multiple times that, and wouldn't have looked right anyway.

[Tom M King]

That company makes the exact same profile, and different sizes, in copper too.

Those are the original 1850 sash that I redid. There were only 18 original panes remaining, so cylinder glass sheets were ordered from Bendheim in Germany (edited to add: the company that sells it is here, but we ordered a whole "case", on a pallet, so they drop shipped it from Germany), and it matched the original almost exactly. http://www.restorationglass.com/anti...ndow-glass.cfm They had all been painted shut, and now operate better than ever, I'm sure.

The sash on the back of that house had been replaced, so on my to-do list is to make four exact replacement sash.

I have all the parts run for those few sash, and modified an old molding plane to match the profile, but I got sidetracked saving a falling 18th Century chimney, and other family stuff, so haven't gotten back to them.

My to-do list is longer than I can possibly ever get done. That's a museum house, and they want me to build a replacement, separate kitchen, which would be one of four that I have requests for, etc., etc.

[Jacob Reverb]

Silver solder is incredibly strong. Probably stronger than the cast iron. But you need to get the cast iron quite hot.

I do quite a bit of tig, stick and oxy-acet welding and brazing, and I agree that silver solder is wonderful stuff, but I would be leery of heating cast iron – particularly something that needed to stay straight/flat or stay put – unless it was absolutely necessary.

Depending on what kind of cast iron it is, epoxy, with a tensile strength of ~ 7.5 ksi, could approach (if not exceed) the tensile strength of the CI. Cast iron is a lot like concrete: Plenty of compressive strength, tensile strength not so much...which is often why it cracks (often as a result of uneven heating/quenching).

If the part isn't too stressed, and not critical, I would lean toward a glue-type solution. FWIW, I've seen epoxy "crack patches" last on raw-water-cooled marine engine blocks for years and years...

Allan, have you fixed it yet?

[Allan Speers]

Allan, have you fixed it yet?

Not yet. I'm still weighing the various options, & performance vs cost.

I should get to it sometime this week. I'll report back & with pics.