New forge upgrade

[paulgatx]

Hi all, I just received my new Hell's Forge 1 burner forge (no time or interest to make my own yet, but I'm sure I will someday).  Based on discussions here, I bought my Kast-O-Lite and Plistix from Wayne Coe to improve thermal properties.  I was also planning on adding another layer of Kaowool before coating in Kast-O-Lite.  And I'm replacing the brick with a kiln shelf.

However, now that I have my forge, I'm debating adding the extra blanket as I'm worried about changing the inner dimension too much.

Questions:

1) Can I add another layer of blanket on top of the Kast-O-Lite and Plistix coating if I decided later to add more?  Or would I need to remove all that first and start over.

2) If I do add the extra liner first, will I have concerns about the burner setup and forge thermal properties?

Thanks.

[Mikey98118]

7 hours ago, paulgatx said:

2) If I do add the extra liner first, will I have concerns about the burner setup and forge thermal properties?

First off, let's start with you telling us whether that is a one-inch or two-inch thick layer of ceramic blanket; but either way your next step is to rigidize the existing layer while is is still in such very good shape.

[paulgatx]

3 hours ago, Mikey98118 said:

First off, let's start with you telling us whether that is a one-inch or two-inch thick layer of ceramic blanket; but either way your next step is to rigidize the existing layer while is is still in such very good shape.

Mikey, the 1" wool that came in the forge is already rigidized.  I checked with the manufacturer and confirmed when I received the forge.  Regardless, the new 1" layer I would add would not be rigidized as it will be coated immediately in Kast-O-Lite.  Wayne Coe advised that no rigidizer is needed in that case.  And I have read on here where some people advise to rigidize first anyway, but I'm going on Wayne's advice.

 

27 minutes ago, WayneCoeArtistBlacksmith said:

Even though you already have your forge you can benefit by reading that attachment and determine that you need a cast interior and infrared reflecting coating (such as Plistix or Metrikote) to increase efficiency.

 

Wayne, sorry, but please re-read my post.  I already purchased the Kast-O-Lite and Plistix from you (I'm waiting on delivery)  so the blanket, whether the 1" it already has or the 2" total after I add another 1", will be coated in both of these.

Regards.

[WayneCoeArtistBlacksmith]

Paul your order was shipped yesterday by Priority mail.

Let me know when I can help you again.

I'm sorry, I guess I just skipped over the first paragraph.

thank you

Wayne

[paulgatx]

Wayne, no worries, I trusted it was coming.

Just looking for answers to my questions now if anyone can help.  I've got a query in to the manufacturer as well about the change in interior volume.

[Mikey98118]

I don't strictly agree with not also rigidizing the inner layer just because you are planning a cast refractory layer for the forge's hot face. What does that refractory layer sit on if not the inner layer of ceramic blanket? After a few heats, the inner layer of blanket will "take a set" becoming quite firm, but not rigid; which is one of the things that rigidizer does. Can you get by without this; obviously, but should you? The answer is a judgment call; I wouldn't go that way without good reason to.

[paulgatx]

OK, input received.  I also agree it obviously can't hurt, was just trying to save cost/time if not needed.  I'll pick some up just in case I decide to add the extra layer. 

Any input on whether the setup will be changed too much by adding the extra layer.  In other words, I assume (maybe a bad assumption) that the burner setup is optimized for the height of the floor (with hard firebrick that I'm replacing with kiln shelf) and volume of inner cavity.  Will I need to adjust my burner by changing those two things?

[Mikey98118]

The setup will be greatly improved by adding the second layer--not extra layer; you need to get that point straight in your mind.

[paulgatx]

Mikey, no need to talk down to me.  I'm not sure that you're curmudgeon status yet.  Haha!  And it is extra by definition since it is added to the "stock" forge.  I stand by my definition, no need to continue this discussion.

[Mikey98118]

 

Whatever; goodbye.

[ThomasPowers]

Please remember that the goal of manufacturing a product is not to produce the best product; but the cheapest one that will sell to a large number of people. 

Adding another layer of refractory insulation generally does not cause issues by decreasing the internal space; but does increase gas efficiency greatly.  However you are the person who has to judge if they type of work you wish to do in the forge merits the decrease in interior space.  For instance: billet welding---greatly improved with more insulative refractory and  a flux resistant liner.  Ornamental scroll work---may need as much space as you can get! (and an armoured inner layer.)

One thing to remember: whatever you choose is temporary!  A gas forge liner is an consumable.  You will be able to change your decision later (and generally the worse the initial decision, the faster you will need to revisit it...)

[paulgatx]

Thanks, Thomas.  So sounds like the burner "setup" will not have to change.

Any input on my second question about whether it's advisable to put the 2nd layer of blanket on top of existing refractory and then adding another layer of refractory on top (so a sandwich of wool/refractory/plistix/wool/refractory/plistix), or to just rip it all out and do wool/wool/refractory/plistix?

Thanks again.

[paulgatx]

Let's forget the last question ... It's moot now.  With no negative impact of changing the interior volume, I'll be adding the second layer of wool.

So now I will have (in order from the outside):. stock steel shell, stock 1" blanket pre-rigidized (maybe I'll add more as it doesn't seem super hard), additional 1" Kaowool blanket rigidized with Simwool rigidizer, 1/4-1/2" Kast-O-Lite refractory, wash of Plistix, alumina kiln shelf.

Sound ok?  Any experience with the Simwool rigidizer, should it be ok for this application?

Thanks in advance.

[paulgatx]

Ok, one more question on this topic (for now).  I've got this question out to the manufacturer as well, so I'll use all inputs.  Related to my concern about changing the interior volume, now that I've got the second layer of 1" blanket in, I'm calculating that my interior volume will go from 265in^3 to 124in^3 with the blanket to 70in^3 with the Kast-O-Lite and Plistix.  Ignoring the problem of the size pieces I can fit in (I'm planning on small stuff to start anyways), that final volume seems much smaller than any other numbers I'm seeing discussed w.r.t. burner capabilities.  Is there such a thing as too small a volume?  I assume this thing is going to be hotter than the hinges of hell at fairly low flow with a 1" burner.  Maybe not a problem unless the burner doesn't function well at such low flow?  If needed I can still pull out the second layer of wool before I apply the refractory.  Or I can go with 1/4" refractory instead of 1/2" to get a bit of room back.

Thanks again in advance.

 

[Buzzkill]

There is such a thing as too small of a forge chamber for a given burner.  The basic principle is you don't want the flame cone to impinge directly on your work or the opposite surface of the forge.  That will disrupt the combustion of the flame and make your setup less efficient and may have negative side effects on your steel.   The rest of this is just opinion.   Ceramic fiber blanket tends to delaminate fairly easily, so if I were in your position I'd probably remove a third to a half of the second layer and go with around a quarter inch thickness of the Kastolite, but would err on the thick side.  It looks to me like you're getting into the half inch diameter burner (or better yet 2 burners of 3/8 inch diameter).  I think with a one inch burner you may find that the flame cone is longer than the space you have available from top to bottom of your forge chamber once you get the Kastolite in place.

[paulgatx]

Good feedback, this is exactly my concern.  However, I did make sure that, in my retrofit, the forge floor is at the same distance from the burner as it was in the stock forge (2.5") since they used a firebrick propped on the edges of the lower half of the oval.  Now, that original setup could be total xxxxx, as Mikey would attest to, but I'm at least trying to keep that parameter the same.  So now the distance would be the same but the volume would be ~ 1/4 with a much higher thermal efficiency.  I'm talking to the manufacturer later this afternoon so I'll see what he says.

Edited May 23, 2018 by Mod34
Edited for inappropriate language