I was just getting ready to do a little more forge practice yesterday (after calling it quits on my stupid plumbing) and as I was setting up and getting ready to do my "dehumidifying" heat on the forge since it had been about a week since I last ran it, I happened to notice cracks in the top of the liner. I assume I should worry about those and get them fixed correct? Or is this a common thing that I should worry about too much? Due to them appearing to originate from the nozzles, I probably didn't do a "dehumidifying" heat on the forge correctly at some point and ran it too hot before it dried out. 

Use refractory cement to heal those cracks before they get worse. Remember to spritz some water deep into them before applying the cement. Give them a day for the cement to set up, and then heat cure SLOWLY.

Got it. Ill have to order some but I will get those sealed back up! Would you happen to have any recommendations for type/brand of cement I should use?

It is best if you use one that is rated for temperatures as high as the refractory; otherwise they are pretty much all the same.

sInDock,

How did the cracks turn out?

I got a replacement liner for the top. I never got around to patching it with any kind of refractory cement. I was able to weasel it out so I think once I get around to it I can patch it and have a back up liner.

You started this discussion by mentioning a dehumidifying heat cycle, so we know you won't forget it with the new liner. But, lots of folks don't bother with that step, which is a mistake.

Yup! I really try to do it every time since I tend to go days without ever lighting it and being in Ohio, it is quite humid most of the time. I normally get all setup, light the forge with the gas turned on just enough that it will stay lit then let it run like that for a few minutes while I get everything else setup. Once I am ready to go it should be all good as well then I just crank the heat up to let it warm up to forging temps.

I think I simply did not let it go long enough at one point which caused the cracks, so I by no means blame Majestic for anything as it was more than likely 99% operator error. All in all, I am quite happy with the forge I purchased from them and have not had any issues outside of this and it works like a charm.

Don't forget the chance it was cracked in shipping or handling. it's reasonably rare but happens that an invisible crack starts at an edge or the burner port or where a nut falls on the liner. Thermal cycling can make them grow until there's a failure. 

Pre-drying / heating the forge gently is one of those, "can't hurt, might help," things.  

Frosty The Lucky.

Out of pure curiosity, could I have kept using that liner? At what point do the cracks cause problems/safety issues that the forge should not be used until a repairs are made?

Unless pieces are falling off I don't worry about cracks. If you notice a hot spot in the shell opposite a crack then it's becoming a problem. If I was seeing problems, I'd probably paint some Plistex over the cracks allowing as much to soak in as possible, dry, repeat a time or two then fire it. This kind of repair is one of the things Plistex is made to do. If that didn't do it I'd look to replacing the liner. 

Other than: shooting SUPRISE flames, burning the propane line or turning the shell red, cracks in the liner aren't really a safety issue. A propane forge IS a fire hazard until it cools anyway. No?

Frosty The Lucky.

I kind of figured that was the case. Speaking of the shell getting hot, I have been meaning to weld up a sort of little stand out of angle iron since the shell has always gotten quite hot and I use a stack of masonry blocks as a stand. The angle iron stand would keep it a little ways off the block and allow air to flow under it. If I forge for awhile, that top block gets hot enough that you can't touch it. I am sure it will start crumbling soon if I keep letting it get that hot.

I put the NARB forge on a couple fire bricks to keep it off it's steel serving cart or the cart would warp. Another good option is using cement backer board on spacers under the forge. A pan of sand makes a good heat shield but can get messy. 

Not being able to touch the outside of a propane forge is pretty normal. 

Frosty The Lucky.

On 6/2/2021 at 3:24 PM, Mikey98118 said:

mentioning a dehumidifying heat cycle,

When our forge has not been used for a while, the night before we are planning to use it I put my shop drop light with a 100 wt incandescent bulb inside to dry the condensation.

That's not a bad idea Iron. I am all about energy efficiency, so only have LED lamps around the house lol. I think I still have a 120W heat lamp from when my Uromastyx was alive that I could rig up a socket for to stick in there. I have noticed that the side walls have become fairly warped as well, once again probably as a result of me not doing a cycle correctly.