Rebuilding forge

[Jimw3326]

After perusing the forum the past couple weeks, I've come to realize I need to change a few things up.

I built my forge about 6 years ago on what I thought was sound info. It does what it was intended to do, just need to make it safer.

It's made from an old compressor tank that the bottom rotted out. Cut the bottom out at the caps and half way up, cut the top in half and rotate.

Lined with 2 1" layers of cera blanket and coated with itc 100 and 296. Floor is a split hard fire brick.

It has 2 1-1/4 linear burners of a design I saw somewhere that I loosely copied, but they do work pretty good.

I'm gonna reuse the tank but with a cast refractory and build better burners.

These are the best pictures I have at the moment.

Any and all suggestions/opinions are appreciated.

[Mikey98118]

To begin with, as much as I can tell from your photos, you don't have any major problems with those Mikey burners, nor with the shape you chose for your forge. If you are redoing the forge interior anyway, this is the perfect opportunity for you to make the two changes that will actually make it more efficient.

Congratulations on choosing an oval shape for your forge; this time, turn it on its side, where it belongs, and decrease its internal area. Doing this will allow you to cut those burner's gas pressure way back, saving about half your fuel use. Your burners have very large turn-down ranges, so you don't need to build smaller burners.

I note that you even followed my advice on what to use for fuel hoses; that more than following my early design, down to the flared end on their choke sleeves shows that you followed something directly or indirectly quoted  from the 2004  book.

[Mikey98118]

Don't forget to put a Plistix 900 F coating on the forge interior.

I also suspect that your burners mixing tubes are just too long. Measure the inside diameter of the tubes, and multiply it nine times, to know how much tube length should exist between the forward edges of you air openings and the end of the tube.

Purchase a cheap (Chicago brand from Harbor Freight Tools) rotary tool, along with a $10 set of tungsten carbide rotary files, and put an internal bevel on the forward ends of your burners air openings; you won't believe how much hotter your forge will get. You could also put extenal bevels on those openings rear edges, but your openings are long enough that they would probably have minimal impact.

[Jimw3326]

6 hours ago, Mikey98118 said:

To begin with, as much as I can tell from your photos, you don't have any major problems with those Mikey burners, nor with the shape you chose for your forge. If you are redoing the forge interior anyway, this is the perfect opportunity for you to make the two changes that will actually make it more efficient.

Congratulations on choosing an oval shape for your forge; this time, turn it on its side, where it belongs, and decrease its internal area. Doing this will allow you to cut those burner's gas pressure way back, saving about half your fuel use. Your burners have very large turn-down ranges, so you don't need to build smaller burners.

I note that you even followed my advice on what to use for fuel hoses; that more than following my early design, down to the flared end on their choke sleeves shows that you followed something directly or indirectly quoted  from the 2004  book.

I'll get some better pics and details this weekend of the burners. Haha, It's not oval but round, just has a rectangular opening the same width as the floor. I kind of need it in this configuration since I toss a crucible in it to melt down brass and copper for knife parts.

My main concern at this time is the fibers being blown out from some damaged areas.

[Jimw3326]

So I go to remove the burner and no-go. Turns out the exit has belled, pretty wild. Also disintegrating. 

It's about an 1 1/2" to long, .8125 id X 8.75 running a .031 tip. I do have the inlet beveled.

With the 2 burners, it would melt a #2 crucible of copper in 20-30 minutes.

Volume is about 990 in3, 10w. X 9h. X 14d. I used 9.5 for the dia.

The volume will reduce a little as I plan to line it with the cast refractory and still use the same depth of blanket, 2".

[Mikey98118]

9 hours ago, Jimw3326 said:

I kind of need it in this configuration since I toss a crucible in it to melt down brass and copper for knife parts.

I see. Good for you

I wish more people would mix and match their metals skills.

9 hours ago, Jimw3326 said:

My main concern at this time is the fibers being blown out from some damaged areas.

The quick fix is patching compound. You can even use Plistix for that, by mixing it with less water.

[Frosty]

Not to butt in here, I don't have anything significant to add but . . . Mike have you read the "ITC-296A" performance data sheet? It has me rethinking things.

https://static1.squarespace.com/static/590381af1b10e352e5d0131a/t/59371525be659415240426f1/1496782118129/ITC+296A+Technical+Data+Sheet+ALT.pdf

Sorry for the huge link, tiny URL doesn't like my OS anymore. <sigh>

Frosty The Lucky.

[Mikey98118]

1 hour ago, Frosty said:

Not to butt in here, I don't have anything significant to add but . . . Mike have you read the "ITC-296A" performance data sheet? It has me rethinking things.

Just yesterday I saw ITC 100 offered at a reasonable price by one seller, so perhaps their products are worth looking into (for the first times in years, in my opinion). So, I will look it up.

[Frosty]

Look at the thermal conductivity comparisons.  In a torch test on 1" 2,600 IFB, 2,500f on the hot face is Room temp on the cold face. 

Frosty The Lucky.

[Mikey98118]

So I looked it up and only found their ad; not a data sheet. But two things were instantly clear: The 5000 F use rating means that it is nearly pure zirconium; and the use rating is completely  irrelevant, because they state that this product must be painted over a base coat of one of only two of their other products, which have far lower use ratings. This seems typical of the double talk that the original company used about heir ITC-100 product, when they described its heat reflection as being "up to" a certain amount. But I found that product to be no better than Plistix, until I modified it.

Also, needing to use two of their products to get the job done, just about doubles its price; I wouldn't buy so much as a cup of coffee from them

 

13 minutes ago, Frosty said:

In a torch test on 1" 2,600 IFB, 2,500f on the hot face is Room temp on the cold face

Over what period of time? The torch test you are referencing makes a standard photo, which has been used to help sell ceramic fiber products, for years. But as we all know, the cold face will reach 2000 degrees in a few minuets.

Corporate culture is like a swamp; easy to dirty up, but unlikely over to flow clean, afterward. I gave up dealing with jerk businesses a long way back.

[Frosty]

The link I sent didn't work? I'll PM the data sheet. Fingers crossed. . . .So much for that, I can't save it as a graphic or cut and paste the page.

Try this link to their product page and scroll down, it has the pertinent links. https://www.itccoatings.com/products-1 This is the ITC product data URL, NOT the sales links hopefully it's not a violation of IFI rules. I'm going to PM it to you just in case.

They don't mention time period but untreated IFB shows between 1,000f and 1,500f heat transfer in the tests. And true, I'm giving ITC the benefit of the doubt it's an honest test of course a large company MIGHT notice it they were bogus results.

I think IR "reflectivity" is a legacy term they aren't likely to change after using it for-ever. If they did I'm sure customers would be demanding the old IR reflective products and looking elsewhere. Sometimes marketing just is what it is.

Frosty The Lucky.

[Jimw3326]

That's how I coated mine but it's not a solid coating. I put the 296 around the openings and gaps. The actual blanket just has the 100 on it. 

BTW Frosty, you're not butting in, I asked for any and all opinions.

[Frosty]

Maybe not but Mike had it well handled so I didn't really have anything to add until I looked up ITC-296A and got a little excited. By what I saw, 296A is all they offer, 296 sans A is the old version and maybe still in stock with some retailers but not from ITC.

I think I'd use both as recommended were I you. The 296 is intended for rough handling and blacksmiths are nothing if not rough on propane forge liners. 

Frosty The Lucky.

[Jimw3326]

I didn't have enough to coat the whole thing at the time so here I am. Old adage 'If you don't have time to do it right the first time, when will you have time to do it over?'. Doesn't necessarily apply here but I think of it every time I have to do something over.

[Mikey98118]

I didn't think you were butting in either. We need to bring up new products, even though "I don't trust nobody."

[Frosty]

I just wanted to point out the ITC products Jim is using doesn't need no help and in fact kind of excites me. 

I find if someone is already doing a good job helping somebody and I try to help a little more it can get confusing, especially for beginners so I'm getting to watch and read until I REALLY think it'll help. Often it's easier for me to say something simply than it is for someone who's intimately familiar and thinking in detail. 

Frosty The Lucky.

[Mikey98118]

3 hours ago, Frosty said:

Often it's easier for me to say something simply than it is for someone who's intimately familiar and thinking in detail. 

Hmm; are we pointing out my various typos and hilarious foo-pas? 'Cause I'm still cringing and laughing over the last one. They probably would have dinged me for it, if they hadn't men so busy rolling on the floor

Just like "men" should have read "been." Ugh!

[Frosty]

Oh NO, your typos are usually too good a giggle to mess up with a correction!

It's just that it's hard not to repeat what you've said a hundred times when someone actually needs to hear it put a different way. Beveling the downstream ends of the air ports has a number of positive effects on performance but listing them when all the guy  needs to  know is where the bevel goes can be confusing. Hmmm?

Frosty The Lucky.

[Mikey98118]

Well, confusion is a permanent state for some, but since we are supposed to be helping, we must put away our Bugs Bunny hats and keep a straight face (darn it).

[Frosty]

In observance of my recentest Ultra Maroon mistake I'll submit to the laughter gracefully. Straight faces need not apply! I'm going to blame the tree and low blood sugar anyway! Yeah, that's what happened it IS! That's my story and I'm sticking to it.

Frosty The Lucky.

[Mikey98118]

After the second stroke I gave up on all that face saving, and whose first-est with the most-ess  baloney.

[Jimw3326]

5 hours ago, Mikey98118 said:

Well, confusion is a permanent state for some, but since we are supposed to be helping, we must put away our Bugs Bunny hats and keep a straight face (darn it).

Wellllll..... Not necessarily! I'm enjoying the banter.

[Mikey98118]

Oh, but we can git a lot sleazier 

[Frosty]

Sometimes we even add Veegum to our vocabularies special. 

Frosty The Lucky

[ThomasPowers]

Just back on; went to the ER for some odd BG readings Nov 10; brain surgery!!!!!!.   Glioblastoma; prognosis perhaps 8 months.....zo I have a good excuse for brain glitches right now!!!!!!!  (sounds like I should be planning a sale t 2023 Q-S....)