Epoxy Question

I'd have thought any of the proprie... brand names. But I would avoid any 'Araldite Rapid'... it is pathetic.

I regularly use 151 a 10 minute double syringe epoxy, which is relatively cheap, effective and cures fairly quicky. (Always allow twice the cure time stated on any adhesive).
Mind I'm generally using it on wood, but on parts that do get some stress.
Most glueing is down to preparation and jigging up. Take the trouble to get it clean and devise a way to have it lightly clamped while curing. Rubber strapping (cut from old inner tubes) is V good for apply tension to unusually shaped objects.

As it is dome shaped it should hold quite well, whereas gluing a flat plate wouldn't give much strength.

I expect JB weld and all the common epoxies will also get a vote too.
Good luck.
Del

J&B Weld is awesome....

http://www.jbweld.com/product/j-b-weld/

JB Weld.

Stuff of the Gods!!

Don't want to bad-mouth J-B Weld, but it is pigmented, black.

I'd use a thirty minute cure,clear epoxy, and not the fast-setting (5minute set) stuff.

Be sure the "adherends" are clean and dry.

Cast iron is black?

Maybe that makes it a perfect choice.

I have seen polished, fancy stoves, though.

Thanks guys, I had thought of JB weld, though never used it myself. I just wanted to see if anyone had any other ideas as well because I don't want to have to do this twice (though it is a possibility , things happen) and with all of the advances in adhesive technology wanted to see if there were any other or possibly better options(I use better in a loose manner as again I have never used JB weld so cannot speak as to it's strength) As this is a very clean break per se, it fits together nicely, if I clean the edges thoroughly and adhere them it should hold up nicely. though I may put a piece of good ole duct tape on the inside seam just in case some kid comes along and picks it up so as hopefully if it does come apart it wont hurt someone since the underside is not seen unless you pick it up. I also suggested to them that perhaps the piece itself should be glued down so as to help prevent it from getting picked up in the first place.

It is helpful, depending on use, if you are patching a crack like this, to put tape on both sides to hold the JB weld in place, as it is quite runny and dries slowly....give it 24 hrs to cure, and it will make an indestructible joint.....You can sand and paint if desired..

I think J-B weld is fine.

About 3 years ago I bonded my inside Al shower door handle back on the Al frame with J-B Weld.

I was anal about surface preparation and cleanliness.

It's lasted that long with a teenage boy using it every day.

Regardless of which Epoxy product you choose/have available, remember that Epoxy cures by exothermic reaction - it needs heat! Cast Iron makes a really good heat sink, so be prepared to warm the cast iron before applying the adhesive. Also many of the old stoves were "Black Leaded" to keep their appearance and which happens to bond well with the crystalline nature of the cast. Black leading is an abherant - the opposite of an adhesive so be sure to clean the mating surfaces with a suitable solvent really well first. I believe most black lead (aka. Stove Polish) in recent years is made from waxes, solvent and graphite. Older ones may have contained carbon black also. Heck of a dirty, smelly job applying the stuff and hard work polishing it up afterwards. Ooops I'm showing my age again :)

time for some 3Dmodeling....

You might also think about keeping it from falling with a magnet.

Thanks, I think you all have convinced me of the benefit of JB weld. I was looking at Loctite fixmaster which is fairly reasonable but cost an arm and leg for the dispenser so I think for the use and that if done properly JB should do fine. The magnet idea also might be a good one to consider as I have a plethora of neodymium magnets available. thanks all for your help.

If you use a tight belt to hold it together while setting, the outside can be cleaned perfectly. The solvent, if needed, can be acetone, I think.

CCI

For a clean fracture with that much contacting surface area and nice clean grain structure why not use "Super Glue? No color problem. Quick dry. Thin layer only needed. No mixing of 2 parts and any concerns of not having a 100% complete mix.

A resounding no to super glue.

Any squeeze-out will be hard to remove and will stain the metal white.

Also, there is the issue of porosity. Acrylic adhesives work best when bonding smooth, non-porous surfaces such as glass and might require a primer/hardener to initiate the cure reaction.

Messy and iffy.

That's my opinion.

I've had incredibly good luck with a product called Miter Bond (Home Hardware stores sell it in Canada, don't know about the USA). It's a 2 part super glue type system; you have an activator spray & glue combination that is easy to use, has a bit of body to fill any porosity, holds like you wouldn't believe & can easily be cleaned off anything that doesn't have the activator on it.

One other idea is to use lead solder for the repair. Lead solder is easy to use and will stick to cast iron. Depending on how clean you want this to look, you can use either paint or marker to cover up any lead solder that flow out.

Thanks folks, the JB weld did the job. I actually bought some but didn't take with me was planning on bringing the pieces back to work on. when I went there he had some JB there, though it was the quick set kind which I didn't want I decided to use it anyway and see how it worked. So far it is a resounding success. There are other pieces that need glued but I do want to give a few days to cure fully before evaluating the results.

thanks all.

best regards,

shawn