Need better burners for my forge

[1justin]

Hi, I'm a machinist and a damascus knife maker, too. I was using the coke forges at my school to make my forge welds, but have since graduated, so no more access to them. Two years ago, I bought a new two burner forge from ebay, before I got into machining and realized I could have made it better and way cheaper. The guy I bought it from boasted how "easy" it was to forge weld with, however it has NC burners that really don't get it hot enough to do any kind of a decent weld at all, even at 20 psi.

Does someone here use T-Rex burners? Can you tell me more about how they work? What pieces are involved, that sort of thing? Like I said before, I'm a machinist and am interested in designing something similar to use in my own forge. Because, the NC burners just don't cut it with making damascus, I get little spots in the middle of my billet where the weld didn't quite take. These spots later expand during the heat treat. Any help would be much appreciated, because I don't have the money to buy one of these burners myself. Does anybody know if hybridburners sells these to vendors? Or are they the only place you can buy one?

Thanks, Justin

[MattBower]

https://dg.box.net/shared/static/s3pjhjalji.pdf

This design is by Daniel Gentile, a very talented Swiss bladesmith, toolmaker, machinist, etc. I own a T-Rex. The T-Rex is similar to any venturi style burner (not sure venturi is quite the right word, but that's the common parlance), it's just better made and they did quite a bit of experimentation to optimize everything. As best I can tell this design is pretty much the same as my T-Rex. Of course Daniel uses metric measurements, so you'll have to convert everything. Sorry about that.

By the way, how's that NC Tool forge insulated?

[Sweany]

*A friend of mine runs NC forges. He uses his 3 burner for making welds in. The knifemaker forge on NCtools page is a 3 burner and has damascus making listed as an attribute...

Is it blacks spots in the weld, or delaminations? Maybe a longer soak time would help?

Personally if you want to make a lot of damascus, get a blown forge design like Jymm Hoffmans.

*my .02,other results may vary

[pkrankow]

If your forge is lined with hard firebrick you may have to let the forge heat fully before attempting to weld. This may be a 30 min to 1 hour wait.

You can do some smaller non-welding forging while it heats some.

Phil

[1justin]

https://dg.box.net/shared/static/s3pjhjalji.pdf

This design is by Daniel Gentile, a very talented Swiss bladesmith, toolmaker, machinist, etc. I own a T-Rex. The T-Rex is similar to any venturi style burner (not sure venturi is quite the right word, but that's the common parlance), it's just better made and they did quite a bit of experimentation to optimize everything. As best I can tell this design is pretty much the same as my T-Rex. Of course Daniel uses metric measurements, so you'll have to convert everything. Sorry about that.

By the way, how's that NC Tool forge insulated?

Awesome, thankyou so much! It is insulated with ceramic blocks. Venturi is the right word (as long as you are talking about the flow of propane sucking in air). It wont be a problem to convert.

One of my burners recently went out, too. It's just too much of a pain to try and get everything lined up perfectly with the NC's, I think this must be the problem b/c its still shooting out propane, but for some reason it doesn't make it thru the neck of the burner. The T Rex says everything is easily adjustable, which is what makes me want to make one of something similar. Does the choke slide up and down on yours? The T Rex guy also says it is machined out of a solid piece of metal and it's not plumbing parts that are re-assembled. Is there any actual benefit to not using welded metal pipe, I can't imagine there would be?

My forge is a two burner, and I really dont want to have to make another entire forge. Is the T Rex really that much hotter than regular NC burners? It doesn't sound like you think so. But I saw on the hybridburner website where they are saying that they have an induction ratio about 1/3 higher than other burners. It seems like this would make them a lot hotter. Anyway, if this burner doesn't turn out that much hotter, do you guys think I should try forced air?

[pkrankow]

By machining out of a billet you can eliminate areas of poor flow and guarantee dimensions improving overall performance.

If you can weld really well, then you can get a very good welded burner, and if you can't or don't want to weld, plumbing parts become convenient and have acceptable performance with a reasonable price tag.

Phil

[1justin]

*A friend of mine runs NC forges. He uses his 3 burner for making welds in. The knifemaker forge on NCtools page is a 3 burner and has damascus making listed as an attribute...

Is it blacks spots in the weld, or delaminations? Maybe a longer soak time would help?

Personally if you want to make a lot of damascus, get a blown forge design like Jymm Hoffmans.

*my .02,other results may vary

They may be Reil burners. Just two pieces of 1" pipe, with a wider 2-2.5" section screwed on top where the propane shoots in. My welds are not contaminated, not delaminations, or inclusions either. Longer soak time helps, but it just wont get hot enough (especially now that one burner stopped working). I'm just sick of trying to make the adjustments with it burning using vice grips and my kevlar glove, half the time burning myself in the process anyway.

The problem with the weld is not that I don't know how to make a good weld. I can do this all day long in a coke forge. The problem is that it gets hot on all sides except the very middle, where I can't see. Maybe, I do need to let it soak more when it looks ready to weld, since propane is much lower temp than a blasting coke fire. Anyway this causes a bubble in the weld, where later on in the heat treat the air expands and makes the bubble very apparent where it wasn't initially. All of my damascus is flat anyway, meaning I dont twist it or do anything that might cause delamination. I have done twists with good success in coke forge welded damascus, I just like the flat patterns more.

[MattBower]

What Phil said. The T-Rex is a great burner and definitely gets hot, but there's nothing magical about the design; it's just better made than a Reil or the like and that amounts to better performance. Smooth flow is more efficient than turbulent flow, the angles are optimized, etc.

Yeah, mine has the sliding choke.

When you say ceramic blocks, do you mean soft firebrick? I'm just looking at the weights on the NC Tool forges online, and wondering if they're using hard firebrick on the interior.

[pkrankow]

Do you work indoors or out of doors? I found the Reil burner a failure because it will not tolerate cross drafts, and I am forced to work out doors. I am using a T-burner that Frosty put me onto, and it tolerates some cross draft, but on a windy day it huffs like a steam train!



Phil

[1justin]

What Phil said. The T-Rex is a great burner and definitely gets hot, but there's nothing magical about the design; it's just better made than a Reil or the like and that amounts to better performance. Smooth flow is more efficient than turbulent flow, the angles are optimized, etc.

Yeah, mine has the sliding choke.

When you say ceramic blocks, do you mean soft firebrick? I'm just looking at the weights on the NC Tool forges online, and wondering if they're using hard firebrick on the interior.

I believe ceramic is different than hard fire brick, but not completely sure. I'm taking a ceramics course and we use a kiln made of hard fire brick which looks something similar to the ceramic block. The ceramic in my forge is a tan color, not sure the kiln is or not.

Mine was not made by NC Tool, just some guy on ebay. So, you wont find my forge on their website. I was just looking online and my burners are definitely not NC burners, they look something like Reil burners without the bell reducer at the nozzle (where the flame comes out) are these EZ burners? I just looked up Ron Reil's design for EZ's and those have a bell reducer at the nozzle too, so I guess these are an extremely cheap hybrid of the Reil's.

[pkrankow]

We are gonna need pictures now. Having a non-standard burner means you need a non-standard answer.

All fired bricks are "ceramic"in the sense that they are fused clays and fillers, however the difference is moot for now. In any case the alternative is a ceramic wool, which is very lightweight. The wool has a higher insulating value than the bricks, but at a sacrifice of durability. There is products like duraboard which are rigid.

Phil

[Fe-Wood]

I made 4 Hybrid burners and use one for annealing copper. I have 3 other bodies that will eventually be in my casting furnace. They are not to hard to make. I took 1" x.o63 wall mild steel and flared it over a mandrel I made and then used 1.75" for the mixing body and 2" for the vent adjustment. I made mine turn rather than slide for air adjustment because I like the easier control. As far as how hot it gets, I'm not sure because it has never been in my forge. It heats .063 copper to anneal heat real fast though and it heated a 160# anvil to 400 in about an hour with resting/soak times between heats.

I am a big proponent for making ones own tools. The experience gained is invaluable FWIW

[MattBower]

My point was going to be that if your forge is lined with hard firebrick it's going to be slower to heat. If it's solely hard firebrick, with no superior insulator (ceramic wool or insulating firebrick) surrounding it, that'll limit the temperatures you can reach. Insulation is important, and hard firebricks don't insulate for squat. Before you start messing with the burners you may want to make sure your forge is adequately insulated. If it isn't, even the best burners will struggle to get it to a good welding heat.

Ideally you want a hard, durable, flux resistant interior (hard firebrick or castable refractory), not too thick, surrounded by a couple inches of a good insulator.

[1justin]

We are gonna need pictures now. Having a non-standard burner means you need a non-standard answer.

All fired bricks are "ceramic"in the sense that they are fused clays and fillers, however the difference is moot for now. In any case the alternative is a ceramic wool, which is very lightweight. The wool has a higher insulating value than the bricks, but at a sacrifice of durability. There is products like duraboard which are rigid.

Phil

Ok, thanks guys. It would be hard fire brick then, if it's all ceramic anyway. I'll try to get some photos up in the next couple of days. However my burners are just two pieces of about 12"x1" pipe with bell reducers at the top and nothing on the bottom. I dont have a lot of room to play around with on the inside, its w6"xh4"xd12" with w4"xh3" openings on both ends. So, can I insulate it with 1/2" of the ceramic wool stuff? I have 5 lbs. of satanite too, what about this?

[MattBower]

Satanite isn't going to insulate any better than the hard bricks. In your position I might think about whether it'd be possible to pull the hard bricks on the sides and top, replace them with wool, and give them a light coat of Satanite. Or it might be simpler to use insulating firebricks, or something like Insboard, rather than the wool

[Sweany]

Ok, thanks guys. It would be hard fire brick then, if it's all ceramic anyway. I'll try to get some photos up in the next couple of days. However my burners are just two pieces of about 12"x1" pipe with bell reducers at the top and nothing on the bottom. I dont have a lot of room to play around with on the inside, its w6"xh4"xd12" with w4"xh3" openings on both ends. So, can I insulate it with 1/2" of the ceramic wool stuff? I have 5 lbs. of satanite too, what about this?

I'M THINKING 2- 1" tube burners are too big for the firebox size. Do you get a bunch of dragons breath out the front?
With all the hard brick you have a lot of heat bouncing out into the atmosphere.

Personally from what I'm hearing the forge could be way better. Line it with kwool and drop the tube size to 1/2" or 3/4"

[MattBower]

I'M THINKING 2- 1" tube burners are too big for the firebox size.

Good point.

[pkrankow]

I'M THINKING 2- 1" tube burners are too big for the firebox size. Do you get a bunch of dragons breath out the front?
With all the hard brick you have a lot of heat bouncing out into the atmosphere.

Personally from what I'm hearing the forge could be way better. Line it with kwool and drop the tube size to 1/2" or 3/4"

I run a single 3/4 inch burner in a 150 cu inch forge with good results, occasionally melting steel. One burner of this size is supposed to be able to weld in a 350 inch fire box.

Phil