fiber blanket temp rating

MarkJeffrey

MarkJeffrey

Joined
Nov 7, 2013
Messages
262
Is there a specific temperature rating that fiber blanket should be for lining a propane forge? What I have found is rated at 2300F , will this do?
 
Mark,

Long time lurker here.

I've only done a couple of stock removal knives just to test designs and my general skills. Haven't done great treats yet, though I do want to make my own forge.

Others here might correct me, but based on my readings on the topic temps used are in the 1600-1900F range, which means you should be okay.

I was looking at fiber of this rating on eBay last year. Think cost was around $50 or a bit more plus shipping.

Good luck with it.
 
Depends on what you plan to do with it. For forging, 2300 is appropriate, and recommended. For a welding forge (damascus) I highly recommend the higher temp stuff that's 2600-2800 degrees. Cerachem blanket, or Inswool HTZ

I'm guessing you're going to just making a bladesmithing forge, so get the regular stuff, it's easier to find and cheaper, and you can use it for occasional forge welding, it just won't hold up to running temps around 2300 day in day out making damascus.
 
Use the HTZ wool (high temp) if at all possible. Just because the forge is running at 2200F doesn't mean the flames are not a lot hotter. The more robust the refractory, the longer the forge lasts between re-lining. HTZ is twice the cost per inch thickness, but much more durable.

If money isn't the prime factor in a forge build, an outer layer of 2" thick regular wool covered by an inch of HTZ wool would make a superb forge from a 12" pipe. With a good refractory coating ( satanite and ITC-100) the forge will purr along and the outer shell won't even get hot.
 
Stacy E. Apelt - Bladesmith said:
Use the HTZ wool (high temp) if at all possible. Just because the forge is running at 2200F doesn't mean the flames are not a lot hotter. The more robust the refractory, the longer the forge lasts between re-lining. HTZ is twice the cost per inch thickness, but much more durable.

If money isn't the prime factor in a forge build, an outer layer of 2" thick regular wool covered by an inch of HTZ wool would make a superb forge from a 12" pipe. With a good refractory coating ( satanite and ITC-100) the forge will purr along and the outer shell won't even get hot.
Click to expand...


Definitely agree with Stacy here. It's especially true if you don't have a pyrometer in your forge to tell what temp you're running. I've seen a lot of forges being run at 2300-2400 (or hotter!) degrees for general forging because people just didn't realize how hot they were operating.

Also, when it comes to insulation, more is pretty much always better. 2 inches is the general guideline you see recommended, and I think that's a good cost+performance baseline, but if you've got the material and the space, 3 or even 4 is better, you can't have too much other than it getting in the way physically.


On the other hand, you have to be careful adding thermal mass (i.e. non-insulating refractories, hard firebricks, etc.) as they can eat short-cycle forging efficiency.

I've mentioned before, but my current large Ribbon Burner forge for welding (24" long) has 7 full sized extreme duty hard firebricks for it's floor (with insulation under it) and a thick coating of a non-insulating castable over the ceramic fiber. I built it to be robust, but I knew it would be a huge heat sink and take a while to heat because of it. This is a fine trade-off in my application, it takes about an hour to reach stable welding heats, but has extremely fast rebound times running 3 large billets (10-20lbs each) but it's an absolute waste of gas to fire it up for less than a 4 hour forging session. On the other hand, averaged out, in 4-8+ hour sessions, it's actually more economical on fuel than without the thermal mass.

Anyway, for general forging, I'm of the opinion, that it's all about insulation, with as little thermal mass as possible. That way, if you'll be at temp in 10 minutes or less, and you're not wasting fuel if you forge for an hour at a time.
 
you also shouldn't have bare wool in your forge. It should be coated with an appropriate type of "cement"
 
I have 2300f wool in my sword HT forge, as it's less expensive for that big chamber, and I won't get up to those temps.
I have always used 2" of 2400f wool in my welding and general forging forges, with satanite on top. I re-line about once a year. Mostly it's flux and students that do the damage. I like the quick heats afforded by blanket lining.
 
Thanks guys, this helps. I'll post pics once I start the build and hopefully I can get some coaching as I go along.
 
You must log in or register to reply here.
Back
Top