Jump to content
I Forge Iron

First and ?last? fire

Recommended Posts

Well then, finally after much procrastinating I reassemble my rivet forge and have m first fire. After a few minutes of struggle getting the green coal to light and smoking out the mosquitos from my yard I get some flame!

I am now as happy as can be and once I get it built up a bit I stick a bent piece of rebar in and start thinking of the projects to come, plant hangers, coat hooks ect.

I pull the rebar from the fire and it is a nice cherry red in the open air, I put it back in and..... !!!BANG!!!

I now have a crack runing half the length of the fire pot.

So now I would like to know:
a) what would cause this? Did I do something wrong or was it just its time?
b)can I fix it? Weld the crack shut? or put a new layer of sheet metal down over the fire pot?

I am hope that this is fixable but if not I will just have to scrounge up parts for a break drum forge.



Link to comment
Share on other sites

It doesn't by any chance have, "CLAY BEFORE USING," cast in the pan does it?

I have a round Buffalo RR forge with worse cracking that that. It has, "CLAY BEFORE USING," cast in All caps in the pan. The layer of clay prevents thermal shock and heat checking. Mine was cracked when I got it and showed signs of being fired un-clayed.

Mine still works, cracks and all but I rammed damp clay about 1" thick into it before I used it. I considered welding it up and may someday but it's not my main forge so am letting it slide for now.

If you want to weld it up ask around first, it's not a beginner's project and you may be better off taking it to a welding shop equipped for welding cast iron. Welding it up is doable but a by the numbers project with a very real probability of making it worse in the process

Fabbing another forge pan is another alternative you might consider. It's a lot easier than welding up a casting that large.

My condolences. :(


Link to comment
Share on other sites

Welding or Brazing something that large and that thin is a hit and miss project even for a proffesional. The Best route is to cut some strips of 1 inch or 1 1/4 inch by 3/16 flat stock about 5 inches long and drill a 5/16 hole centered in each end, then very carefully using a pipe bar clamp gently and slowly pull the crack back together (it doesn't have to be real tightly closed) or just leave it as is and position the straps centered crossways of the crack on the outside and drill a hole and put in a short bolt with lock and nut and tighten it up, then drill the other hole and put the bolt in (lock and nut to the outside). One strap close to each end and 2 more spaced between, then put a layer of clay on the inside as instructed in the above posts.

The most likely cause of the cracking is either too hot a fire to quick or letting the fire spread in size, part of fire management is learning to control the size of the fire for the task at hand. Those small forges don not have a real fire pot perse, the fire is just on top of the bottom of the forge pan.

Link to comment
Share on other sites

I had a Canedy Otto forge crack one cold morning ( probobly 2'x 3' table ). Crack was from pot to far side ( complete to the rim ). I did like Junior suggested with the exception of using 1 1/4" angle iron and whatever bolts I had ( probobly a couple of 3/8 ). Drilled the angle first, drilled one end of the forge through the angle ( I guess 1/2 "thick table ), installed bolt LOOSELY and then drilled other end of the angle. I brought the bolts up finger tight and then a bit more. I used this table for I guess another 6 months until I located another ( and then built the current forge after that ). Your Mileage May Vary. I was nervous when using the forge, yes.

Link to comment
Share on other sites

I have a very similar forge to yours, in that it is a rivet forge... I've always had some sort of refractory material in it, be it refr. bricks or just lime from the liming of our fields. I recently used fireplace mortar and refractory bricks to fabricate a firepot for my rivet forge. I used a 3" wide masonry chisel and scored the bricks to make a slanting edge which turned into the slanting edge of my firepot. I did this for the four sides and then basically filled in as much of the rest of the pot on the backside of my firepot as I could, up to about .5-.25" from the rim of the forge. Then using fireplace mortar that came in the caulk-like tubes that you need the little gun for I filled in all the joints of the firepot and backfilled as much as I could. After about 3 hours of burning cardboard and wood scraps to cure the fireplace mortar, I ran a coal fire hot enough to forge at for about 20-30 minutes for the final cure. After doing some more light forging the fireplace mortar is as hard and solid as a brick and I can actually get my forge up to welding temps. So, you may try just using some strapping and bolts to keep the crack from spreading, after drilling out the end of the crack like I believe irnsrgn said. Clay would work just as well, but this is what I had on hand, and I haven't had any problems at all with it. Good luck. Also, my forge is stationary and never moves, so clay may be a lighter route if you are moving it in and out of shelter. good luck.

Link to comment
Share on other sites

As it was touched on here but maybe not specifically pointed out, you should first "stop drill" the very end of the crack. Then proceed with whatever plan of bracing you choose. to "stop drill" a crack simply means to put a hole at the end of the crack, or just ahead of and inline with the crack. Forces travelling down the length of the crack will cause it to continue in the direction it is travelling. The drilled hole (1/4" or so) will diffuse these forces in all directions and keep them from being focused along the direction of the crack. Good luck. Dan:)

Link to comment
Share on other sites

Well, first thing I did now was go out and look to see if it dose say "Clay befor useing", luckily no, so my wife had to stop laughing at me :).

I am going to go the route of the flat "straps" as the crack closed up pretty good once it cooled down. And there is no need to "stop drill" as the crack runs all the way from the blower hole to the edge.

After that I will add the clay/mortar. Would any type of clay work? There is a fire place store close to my parents house that I will try for the mortar and bricks.

Fianaly I am going to my in-laws this week and they have a forge for me to use, will I have the same problem there? Or can I use this one with out clay?

Thanks for all the advice folks!


Link to comment
Share on other sites

I had that exact same forge; used it for over a decade before mine cracked---first fire after a long hard winter. I think there was some thermal stresses in the cast iron.

I put a mending plate on mine and used it another 5 years before switching to a lighter homebuilt one for my travel forge.

If cracking worries you go to a steel sheet/plate forge as it generally won't crack---will warp on you though.

You could build a steel forge body that you can drop that firepot in and use that.

BTW I made a replacement firepot for my forge from the axle covers from a 1930's banjo rear end, ground out the bearing and ridges and welded on an air pipe and ash dump. Got the covers as a pair of jackstands at the fleamarket for US$3 and have been using the same *one* for over 15 years now as my primary solid fuel forge firepot; the other is a backup for when the first one wears out...the original one is now it it's third forge body and still going strong.


Link to comment
Share on other sites

No, you don't need to line the pan on the larger forge with clay, I don't and haven't had any problems. I have two identical forges to yours. It is a Canadian Blower & Forge Co. brand that I use for my demos. The two bolt holes in the pan closest to the firepot are for mounting the cast iron blower pipe at an angle to either corner, allowing the blower to be mounted for left- or right-handed use. The cast pipe has a clamp on the end to which the blower is mounted directly to it, without any separate stand or bracket. The blowers are considered a medium-size; there are many smaller ones and a few larger sizes. The blowers are quite durable, though you may have to replace the wood on the crank handle. The firepot is a bit shallow for my liking, so I crop in the coal and raise the height by using two short pieces of angle iron; this also saves having coal all over the hearth.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...