Please help,Anybody know what this Red Clay is.....

[Sparticus]

Hello Anyone,
I own an older Harman TL200 and am in dire need to find out what this red clay insulating material is that's been applied to the Afterburner Hood Weldment(Cast Iron) from the Harman factory back in 2008(Last year TL200 produced) as it's clearly NOT a hard cement as I was told from Harman stove dealer's because it's pliable/soft,staining and I'm trying to find out if anyone know's where to buy this red clay...Is it similar to 3M Fire Barrier Sealant CP 25WB+ Intumescent ?
My wish is to obtain advise on whether I should remove ALL this red clay sealant application that's on this cast iron weldment and just apply an insulating furnace cement like Rutland or Hercules then affix the ceramic silicate insulation board or blanket upon reassembly.
I have a suspicion that furnace cement will not adhere to this red clay insulation ?
I hope to receive some type of assistance as my wood stove's down and as of Feb. 26 thru Mar. 26 I've burned up 125 Gal. of #2 heating oil (Rancher's Thermostat set between 60-65 degrees F) .
I'd greatly appreciate any clarity on this mystery red clay as I know this cast iron piece is a bit warped,I try real hard never to overfire at 600 deg. F,and must get this stove operational again.
I love this Top-Load wood stove and am stuck with it as money's tight.

 

[Diabel]

I believe this is a chemical reaction when cast iron is seriously overheated.

 

[begreen]

That was my first thought, it may be some sort of oxide. I would try to meet up with the service man for your nearby Harman dealer and ask.

 

[Jan Pijpelink]

Iron (III) oxide is red pigmented and often used as an anti rust agent for welding cast iron. I am not saying this is the case with your stove, but it could be very well.

 

[Sparticus]

Hey Ty for responding however,this red clay's NOT from the stove being overfired as it was applied by Harman prior to 2008. I guess I'm gonna have to post inquiries to every Harman dealer,as I can and, see if someone might provide an educated answer to this red clay mystery?
Thanks again begreen !

 

[Sparticus]

Iron (III) oxide is red pigmented and often used as an anti rust agent for welding cast iron. I am not saying this is the case with your stove, but it could be very well.

Ty sir for the insight however,this stuff's similar to 3M Fire barrier Sealant CP 25WB+ Intumescent yet i'm unsure of it's Fahrenheit heat tolerance range or whether it can be used inside a wood stove?
TY again for the response.

 

[Diabel]

I have taken apart few old VC (cast) stoves and all the inner cast parts that were covered in that red pigment were bent out of shape. Any cast parts that were plain black/grey were in good shape nice and straight.

 

[Jan Pijpelink]

Ty sir for the insight however,this stuff's similar to 3M Fire barrier Sealant CP 25WB+ Intumescent yet i'm unsure of it's Fahrenheit heat tolerance range or whether it can be used inside a wood stove?
TY again for the response.

The melting point of Ferro(III)oxide is 2800+ F, it starts to decompose at 220 F. You might be looking at the decomposed material. Decomposed or not, the functionality, anti rust, still stands. My 2 cts.

 

[Sparticus]

I have taken apart few old VC (cast) stoves and all the inner cast parts that were covered in that red pigment were bent out of shape. Any cast parts that were plain black/grey were in good shape nice and straight.

Ok TY for the response however this cast iron piece in the bottom photo is OK-very little warpage and the top photo is one that's real warped ie splayed,cracked,etc. however,this red clay was and as I believe applied to this part at the harman stove co. upon assembly,pre-2008. It appears to be similar to a fire barrier sealant ex.3M CP 25WB+ Intumescent and does not resemble cured furnace cement.

 

[Sparticus]

The melting point of Ferro(III)oxide is 2800+ F, it starts to decompose at 220 F. You might be looking at the decomposed material. Decomposed or not, the functionality, anti rust, still stands. My 2 cts.

Sir,you seem to be an expert in regard to this Ferro (III)oxide and would like to know if I should try to scrape all this stuff off and apply furnace cement then reinstall the ceramic calcium silicate insulation ? Will furnace cement adhere itself to this Ferro(III) oxide?

 

[Jan Pijpelink]

Sir,you seem to be an expert in regard to this Ferro (III)oxide and would like to know if I should try to scrape all this stuff off and apply furnace cement then reinstall the ceramic calcium silicate insulation ? Will furnace cement adhere itself to this Ferro(III) oxide?

I am not a stove expert, just a simple chemist. I would seek advice from a stove supplier. When you decide to clean it up, do not use water, it will not dissolve. Try a solution of EDTA which is Ethylene Diamine Tetra Acetic acid, it will dissolve the Ferro(III) Oxide. I do not know if it will adhere to stove cement. Again, call a stove dealer, they probably all will know what you're talking about. I cannot believe Harman is the only manufacturer who applied this material in their production process.

 

[Sparticus]

Sir,you seem to be an expert in regard to this Ferro (III)oxide and would like to know if I should try to scrape all this stuff off and apply furnace cement then reinstall the ceramic calcium silicate insulation ? Will furnace cement adhere itself to this Ferro(III) oxide?

The melting point of Ferro(III)oxide is 2800+ F, it starts to decompose at 220 F. You might be looking at the decomposed material. Decomposed or not, the functionality, anti rust, still stands. My 2 cts.

Hello Mr. Jan.P. please excuse me as this may seem as if I were arguing or challenging you however,I am not and would appreciate any suggestions on how to remedy this cast iron piece as the cost of a replacement run $460+, which I don't have and realize that oxide rust might be what i'm dealing with ?

 

[Jan Pijpelink]

Hello Mr. Jan.P. please excuse me as this may seem as if I were arguing or challenging you however,I am not and would appreciate any suggestions on how to remedy this cast iron piece as the cost of a replacement run $460+, which I don't have and realize that oxide rust might be what i'm dealing with ?

I think you misunderstood The Ferro(III) Oxide, if that is what it is, was applied to the stove plate to avoid rust. There are 3 types of Ironoxide,
(Iron = Ferro). This type is an ANTI RUST agent. If you can clean it up, apply stove cement, make it all airtight, I think you're good to go, but call a stove dealer first.

 

[Sparticus]

I am not a stove expert, just a simple chemist. I would seek advice from a stove supplier. When you decide to clean it up, do not use water, it will not dissolve. Try a solution of EDTA which is Ethylene Diamine Tetra Acetic acid, it will dissolve the Ferro(III) Oxide. I do not know if it will adhere to stove cement. Again, call a stove dealer, they probably all will know what you're talking about. I cannot believe Harman is the only manufacturer who applied this material in their production process.

Wow,it's nice to meet a chemist and I'm greatly appreciative of your help and as the guy from Ottawa,CA has stated it might just be oxide rust leftover from decomposed iron,IDK ? I googled Ferro(III)oxide and it's used for alot of applications ie,pigmenting,welding,etc.-this may just be a byproduct of an overfired piece,although i strictly monitor the stove pipe thermometer temp to NOT rise above 600 F and reduce air controls to lower the temperatures to normal burn temp. rates.

 

[Jan Pijpelink]

@bholler. Any suggestions or input?

 

[Sparticus]

@bholler. Any suggestions or input?

are you suggesting I write to this guy bholler from central<PA or try to invite him to this conversation for his input?

 

[Jan Pijpelink]

are you suggesting I write to this guy bholler from central<PA or try to invite him to this conversation for his input?

No, I asked him to chime in. He will, wait for a little bit. He is very knowledgeable.

 

[begreen]

I would pursue multiple Harman service people. Ask if there is a service manual that might answer your question. Ask about the larger TL300 too.

 

[bholler]

@bholler. Any suggestions or input?

I dont know it looks kind of like hightemp silicone that someone possibly tried to use in the stove. It fluffs up and gets powdery when over heated. But its just a guess i have never seen it on any of the harmans i work on.

 

[bholler]

But those parts look pretty cooked. They were not great performing stoves in good condition. I would be saving up for a replacement asap.

 

[jetsam]

Ty sir for the insight however,this stuff's similar to 3M Fire barrier Sealant CP 25WB+ Intumescent yet i'm unsure of it's Fahrenheit heat tolerance range or whether it can be used inside a wood stove?
TY again for the response.

3M CP 25WB+ is latex caulk. It has a maximum service temperature of 180°F, though they recommend not exceeding 120°F continuously. It is made to expand and plug gaps temporarily in a fire emergency; it (like most "fireblock" products) is not good for any high temperature application.

Never put latex caulk or polyurethane foam on your stove, no matter how many times it says "fireblock" on the can.

If you need a putty to seal a gap temporarily, furnace cement might be suitable.

 

[Sparticus]

3M CP 25WB+ is latex caulk. It has a maximum service temperature of 180°F, though they recommend not exceeding 120°F continuously. It is made to expand and plug gaps temporarily in a fire emergency; it (like most "fireblock" products) is not good for any high temperature application.

Never put latex caulk or polyurethane foam on your stove, no matter how many times it says "fireblock" on the can.

If you need a putty to seal a gap temporarily, furnace cement might be suitable.

Ty Jet in regard to that 3M fire sealant (MSDS capabilities) as I was kinda sure that it wasn't a real high temp product for inside stove repair. A tube of 3M CP 25WB+ was given to me by a welder,whom I asked about the red clay.The 3M fire barrier sealant was my false interpretation of what this red,claylike,oxide appeared to represent.

 

[Sparticus]

But those parts look pretty cooked. They were not great performing stoves in good condition. I would be saving up for a replacement asap.

TY bholler ,fellow Pennsylvanian, for your input however,$'s very tight and a new stove's not in the budget.
I'm thinking on trying Mr. Dan's EDTA acid etch to remove the red oxide then, coat with high temp paint.Then maybe applying a thin layer of high temp. furnace cement over that ? Your thoughts?
I really enjoy the Top-Load of this Harman and it was suggested by Mr. Dan Hechler that the Jotul or Quadrafire top-load woodstoves were more forgiving(Overfire internal damage) but,for now I shall attempt to salvage what I have and save up for a stronger model.

 

[begreen]

Just wirebrush the parts. No need to paint or etch.

What is the expected total cost of repair? It could be that the stove still won't burn properly and sinking hundreds into it now may only buy a year or two. Is it worth it? There are stoves on the market for under $600 that could replace this. It would be good to do the cost benefit analysis of the repair.

https://www.menards.com/main/heatin...e-250-1-000-sq-ft/cb00001/p-1444444138186.htm

 

[Sparticus]

I am not a stove expert, just a simple chemist. I would seek advice from a stove supplier. When you decide to clean it up, do not use water, it will not dissolve. Try a solution of EDTA which is Ethylene Diamine Tetra Acetic acid, it will dissolve the Ferro(III) Oxide. I do not know if it will adhere to stove cement. Again, call a stove dealer, they probably all will know what you're talking about. I cannot believe Harman is the only manufacturer who applied this material in their production process.

Hello Mr. J.P. would you be able to suggest where I'm able to acquire some of this EDTA acid etch,a mf.,if it's available to the public? I've worked with acids in the past like Muriatic(swimming pool)Hydo fluoric or hydocdhloric(Glassware etching of thermometers)? My thoughts are to try and contact the Chemistry dept. at my local community college and see if they be of any assistance? Your thoughts would be greatly appreciated ?