Recommendation? Advice on Forges

Diego_B

Diego_B

Joined
Aug 17, 2020
Messages
260
Hey y'all, so recently I have been wanting to turn in the direction of doing some forge welds on some San Mai and such. But I realize that forge welding takes a toll on your forge really quickly. As of right now I have this.

https://www.ebay.com/itm/DFPROF2-1D...4d079c2058712f12381b|ampid:PL_CLK|clp:2334524

Too be honest with you I like it so far and I've had it for just over a year now, the biggest thing that bothers me though is that it is only insulated with 1in of Ceramic wool and a coating of satanite I think is what it is. I feel that there isn't quite enough insulation and I was thinking of adding 2in of the ceramic wool instead of the one inch, however I think by adding 2 inches it would make the forge opening significantly smaller as its only designed to hold a 1in layer. So right now I'm thinking of building a different forge and was thinking something along the lines of this.

I'm not sure is something like this would be sufficient for me or not? But what I'm looking for is something that I can repair when needed like change out the fire bricks or such and something that has the proper insulation needed to forge weld sufficiently.
 
I’ve been looking for a new forge for months and months. I couldn’t find what I wanted ideally or something wasn’t in stock or too costly for what I felt I was getting

I finally took a forge building class and in a day I made forge that gets to welding temp in 5 mins.

I’m no expert on forges. You seem to be focused on the liner materials and I think heat is more important. In other words, do the burners put out enough heat? I don’t think the insulation concern is as important

I’m using 1” kaowool. It’s simple and easy to replace and you just have to do that. Bricks go on the bottom

it’s not pretty but this one works amazingly well

zFvDnPQ.jpg
 
Yes the burners I have seen to put out enough heat I just don’t run them as high as I would I guess because I run them fairly low. I think I’m just concerned that with only 1in of insulation it’s not enough and I may be using more fuel than I need.
 
HSC /// said:
I don’t think the insulation concern is as important
Click to expand...

Sounds like he's more concerned about the flux destroying the liner. Which from everything I'm reading is a legitimate concern.

I'm no expert by any means whatsoever, but all the the threads I've read on this here suggest using the harder firebricks on the floor of the forge, as that can be replaced easily once the flux starts eating it up.
 
Ron Raducanu said:
Sounds like he's more concerned about the flux destroying the liner. Which from everything I'm reading is a legitimate concern.

I'm no expert by any means whatsoever, but all the the threads I've read on this here suggest using the harder firebricks on the floor of the forge, as that can be replaced easily once the flux starts eating it up.
Click to expand...

yes, I use the thin hard bricks on the bottom, AFAIK, there's no way around the flux destroying the liner.
 
Ron Raducanu said:
Sounds like he's more concerned about the flux destroying the liner. Which from everything I'm reading is a legitimate concern.

I'm no expert by any means whatsoever, but all the the threads I've read on this here suggest using the harder firebricks on the floor of the forge, as that can be replaced easily once the flux starts eating it up.
Click to expand...

Yes that is some of my concern however I think I can counter that by add a coating of satanite and firebricks for the floor like I do now. But mainly what I want to know is if my 1in of insulation is enough for forge welding tasks? I do notice that my forge gets fairly hot on the outside and I know it will cause it’s a forge, duh. But I feel like It shouldn’t be getting as hot on the outside.
 
Diego_B said:
Yes that is some of my concern however I think I can counter that by add a coating of satanite and firebricks for the floor like I do now. But mainly what I want to know is if my 1in of insulation is enough for forge welding tasks? I do notice that my forge gets fairly hot on the outside and I know it will cause it’s a forge, duh. But I feel like It shouldn’t be getting as hot on the outside.
Click to expand...
Short answer- yes
 
Also would a forge like in the video that I posted above work as well? Or would the flux from forge welding eat through the bricks too fast?
 
I find the simplest forge floor is a layer of Bubble Alumina or Cast-o-lite 30. It will last for several years before re-doing it.
Some shops just put a layer of kitty litter on the forge floor and scoop it out and change it every week or so ( depending on how many welding days you do a week).
 
Stacy E. Apelt - Bladesmith said:
I find the simplest forge floor is a layer of Bubble Alumina or Cast-o-lite 30. It will last for several years before re-doing it.
Some shops just put a layer of kitty litter on the forge floor and scoop it out and change it every week or so ( depending on how many welding days you do a week).
Click to expand...

So to do this in a forge would I just apply my Ceramic wool on the floor and then cover it with the Cast o lite and that would be my forge floor? I’m worried about puncturing the forge floor and the wool.
 
A properly lined forge made with Inswool and satanite isn't all that fragile. Putting 3/8" to 1/2" of cast-o-lite 30 or bubble alumina on the floor over the wool/satanite should be rock solid. In a round forge, just make a flat floor by filling the curved bottom (over the wool) with the refractory.

If you want to use the forge mainly for welding, use Hi-Z Inswool.
 
Diego_B said:
Also would a coating of this over the Ceramic insulating blanket be ok? And then a coating of say ITC-100 over that?
https://www.amazon.com/MEECOS-RED-DEVIL-610-Refractory/dp/B00ACIWN9Q
Click to expand...
I used that stuff and it does work - sorta anyway. MUCH better is to listen to Stacy and follow what he says. That's what I "finally" did when building my forge and it's a GREAT success. No point in my writing how or what I did - Stacy already wrote it out.

Thank you Stacy

Ken H<
 
Wondering if one could use some cement board siding (Like HardieBoard) as a sacrificial bottom? Even coated with some insulating cement.
 
You are welcome Ken.

I would not use that Red-Devil mortar for building a forge. The standard refractories are readily available from places like High Temp Tools and Refractory, as well as most knife suppliers. 1/4" of Satanite is hard to beat as a basic refractory over the wool. Bubble Alumina is probably one of the best floor coverings for flux resistance.

For a simple starter forge, 1" Ins-wool, covered with 1/4" of satanite is sufficient. A simple venturi burner is fine here.
For a more robust and efficient forge, 2" Ins-wool covered with 1/4" of satanite and a final 1/8" coat of ITC-100 is good. A 1" blown burner is best here.
For a welding forge, 1" of Ins-wool, covered with 1" of HTZ Ins-woo (high temp)l, covered with 3/8" of satanite, covered with 1/8" of ITC-100 will get the max heat. A 1.5" blown burner is best here, but a 1" blown burner will work.

Building a PID controlled forge is also a good thing. Firstly - it will give you an idea of your forge temperature. Secondly - It will allow you to control the forge temperature much more accurately. If you are going to do HT in a forge, a PID controlled blown burner will help a lot. It does not need a large blower for HT. You can build a 3/4" burner powered by a hair dryer for HT. (Those old bonnet and hose style hair dryers in a case sell for $5-$10 at thrift stores. They make a great blower for a small blown burner. Your mom may have one in the basement/attic.)

Additional forge building tips:
If building your first forge, make it simple and smaller. A 14" piece of 8" pipe (or any cylindrical steel/iron object) will make a great starter forge.
Atlas Forge and Tool company sells several sizes of plug-and-play burners with hose, gauge, and regulator for a very affordable price.

Use Ins-board for the ends of smaller forges. It can easily be cut to snugly fit the end of the forge pipe. Mortar it in with some stove cement or Satanite.

On larger forges, use sliding Ins-board ends to open and close the ends. Weld on angle iron on each end to make upper and lower "U" channels the Ins-board can slide between. 1/2"Ins-board is sufficient for sliding ends. This works better and looks neater than stacking firebricks (which work fine, too).
On a welding forge, you can use 1" Ins-board to make fitted ends with a 6"X6" square opening, and use the firebricks to control the size from there.

Most welding shops will give you (or sell for a few dollars) an old welding gas tank that didn't pass inspection. Get the largest (fattest) one they have. Try and get a 280 or 340 cu.ft. tank. Cut the top off (observe all safety guidelines), and then cut a 18" section off. This will give you a good piece to make a forge as well as top notch quench tank. Weld three short pieces of 1/4" rod on the inside of the cut off top and it will make a perfect cover for the quench tank. For legs on the forge, weld on four RR spikes.

A 16" to 20" section of 10-12" pipe/cylinder will make a great welding forge. Use 2" of insulation. A single good size blown burner will be sufficient.
 
Diego_B said:
Hey y'all, so recently I have been wanting to turn in the direction of doing some forge welds on some San Mai and such. But I realize that forge welding takes a toll on your forge really quickly. As of right now I have this.

Too be honest with you I like it so far and I've had it for just over a year now, the biggest thing that bothers me though is that it is only insulated with 1in of Ceramic wool and a coating of satanite I think is what it is. I feel that there isn't quite enough insulation and I was thinking of adding 2in of the ceramic wool instead of the one inch, however I think by adding 2 inches it would make the forge opening significantly smaller as its only designed to hold a 1in layer. So right now I'm thinking of building a different forge and was thinking something along the lines of this.

I'm not sure is something like this would be sufficient for me or not? But what I'm looking for is something that I can repair when needed like change out the fire bricks or such and something that has the proper insulation needed to forge weld sufficiently.
Click to expand...

Since you've already got the forge, why not use it? Don't worry about "only 1" of insulation", when it burns out then replace with 1 (or 2) inches of good insulation. I find this stuff works pretty good:
https://www.ebay.com/itm/201588565559 It seems to work just fine to use two layers of 1" if you really want 2" of insulation. You just might be surprised how long your existing forge lasts before needing to replace.

Biggest problem I see is the forge body - it's only 10" long and is about 1/32" thick (21 gauge) metal. My thinking is the best "first" improvement is to put a way to read internal temps so you have an idea when you get to the 2200°F desired temp for forge welding. A simple 8 gauge TC with a way to read.
https://www.amazon.com/dp/B018QHQSB8/ ($22 shipped) and perhaps this TC https://www.ebay.com/itm/402680944116?

Drill a hole in the side of your forge away from directly under the flame.
 
That’s
Ken H> said:
Since you've already got the forge, why not use it? Don't worry about "only 1" of insulation", when it burns out then replace with 1 (or 2) inches of good insulation. I find this stuff works pretty good:
https://www.ebay.com/itm/201588565559 It seems to work just fine to use two layers of 1" if you really want 2" of insulation. You just might be surprised how long your existing forge lasts before needing to replace.

Biggest problem I see is the forge body - it's only 10" long and is about 1/32" thick (21 gauge) metal. My thinking is the best "first" improvement is to put a way to read internal temps so you have an idea when you get to the 2200°F desired temp for forge welding. A simple 8 gauge TC with a way to read.
https://www.amazon.com/dp/B018QHQSB8/ ($22 shipped) and perhaps this TC https://www.ebay.com/itm/402680944116?

Drill a hole in the side of your forge away from directly under the flame.
Click to expand...

I was just looking today actually at getting some more Ceramic wool to redo my forge but I am going to try and fit 2 1in layers or insulation and then order me some Satanite or something and then maybe some ITC-100 for the reflective properties. Should I be applying a rigidizer before applying the Satanite or is it just fine the way it is?

Thank you everyone for helping me so far. You all are helping me more than you know.
 
I used to use rigidizer, but I think most folks just apply the satanite now. What I did on the last forge build was make a thin satanite mix up and apply it. After that dried, I put on the regular coating. The thin stuff soaks in a bit and makes the wool stiffer.
 
Stacy E. Apelt - Bladesmith said:
I used to use rigidizer, but I think most folks just apply the satanite now. What I did on the last forge build was make a thin satanite mix up and apply it. After that dried, I put on the regular coating. The thin stuff soaks in a bit and makes the wool stiffer.
Click to expand...

Ok thank you Stacy, I will try that out.
 
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