Oklahoma Joe Longhorn Combo, Mod Questions!

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sjturbo

Fire Starter
Original poster
Jun 5, 2010
35
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Long time since I was last on the forum. That is because I did not get the smoker I was looking for until a week ago. I just finished assembly of  my OJLH Combo and have a few questions about the mods I have read about. I am planning to install LavaLock gasket to the fire chamber and the smoking chamber as several have suggested. I have seen several people install the gasket to the lip welded to the barrel that the lid rests on. Problem is the width of the lip is less than the 1/2" gasket. Has anyone tried sticking the gasket on the lid itself? I though this would accomplish two things; More surface for the self stick gasket to adhere to and insulate the gasket adhesive from some heat. Another question is since the smoke chamber is only 19" wide on the combo is the "tuning plate" still necessary, and if so how have some of you configured it? Lastly I noticed that some had used the Permatex  Ultra Copper RTV to seal between the fire box and the smoker box. I need to seal between the door lip and barrel on the smoker box as it is not welded tight to the barrel. Could this create a health hazard? These questions may seem overboard but I'm just trying get the most out of the unit. Thanks in advance for your thoughts!
 
Well I'm not quite sure why I have not gotten any responses but let me see if answering my own questions I get some of it right.

*Mounting the gasket to the lid will work because where ever the lid goes the gasket will seal.

*Do I need a tuning plate? Well likely I should use a baffle to direct the smoke down and possibly some narrow tuning plates to   stabilize  the temp. But I should do some dry runs and monitor the temp to see it I even need them.

*Regarding which RTV to use - Since they all outgas formaldehyde I guess that a mute point. Good thing is the ultra copper outgases at a higher temperature. Thanks.
 
Thanks SmokinAl!

I appreciate the link, I had not tried OK Joe. I'll let you know!
 
Well I'm not quite sure why I have not gotten any responses but let me see if answering my own questions I get some of it right.
*Mounting the gasket to the lid will work because where ever the lid goes the gasket will seal.
*Do I need a tuning plate? Well likely I should use a baffle to direct the smoke down and possibly some narrow tuning plates to   stabilize  the temp. But I should do some dry runs and monitor the temp to see it I even need them.
*Regarding which RTV to use - Since they all outgas formaldehyde I guess that a mute point. Good thing is the ultra copper outgases at a higher temperature. Thanks.


I have had my longhorn for 5 years now. I can not speak to the gasket bc I do not have one on it. I did however enlist the help of a local welder to do some mods on it. I'll start off by sayin he only charged me $75 bc he used some scrap steel he had. We relocated the smoke stack to the same side as the fire box. We also welded two plates from the inside of the cooker. It comes down over the opening (vertically) and leaves about 3-4 in gap from the bottom of the opening. The second plate was attached to the first (horizontally) across the cooker leaving about 5-6 in from the wall. This makes it a reverse flow. Which I have loved bc of the consistent temps across the whole cooker. I have a temp difference of 10-15 degrees end to end. If you have any other questions I would be happy to share my thoughts.
 
Thanks for the reply zmaxa86! Sounds like you did some effective mods. The reverse flow sounds like the way to go on the full size Longhorn and the temp difference indicates that!  Since I have the combo the cc is much smaller and would not be a good candidate for that mod. Thanks again for the response. I guess not to many people have the combo.
 
 
Thanks for the reply zmaxa86! Sounds like you did some effective mods. The reverse flow sounds like the way to go on the full size Longhorn and the temp difference indicates that!  Since I have the combo the cc is much smaller and would not be a good candidate for that mod. Thanks again for the response. I guess not to many people have the combo.
I'm having one delivered on Friday. I won't get around to putting it together until Sunday but I'll see what I can come up with. From the floor model I looked at I'm guessing I'm not going to do much more than gasket the fire box door and lower the chimney to start.
 
Thanks for the reply zmaxa86! Sounds like you did some effective mods.
 
I'm having one delivered on Friday. I won't get around to putting it together until Sunday but I'll see what I can come up with. From the floor model I looked at I'm guessing I'm not going to do much more than gasket the fire box door and lower the chimney to start.
Well, Any progress on your side? I finally got mine together, stock. I did use Permatex Red High Temp Gasket sealer. Supposed to be good to 600'. must have not let it cure long enough because did some out gassing during initial burn in. Will try again. During the first burn got to 250', likely need to take it to about 400'. Temp at the cooking grate was 250' at the firebox side and 200' on the other side. Need to come up with a diq baffle to even the temp out. The chimney extension has been a pain because the 3" dryer vent does not fit well. How about you? The grill side gets very hot very fast! Almost too hot. Very hard to keep the temp low. Looses heat fast when opening the lid.
 
 
Thanks for the reply zmaxa86! Sounds like you did some effective mods.

Well, Any progress on your side? I finally got mine together, stock. I did use Permatex Red High Temp Gasket sealer. Supposed to be good to 600'. must have not let it cure long enough because did some out gassing during initial burn in. Will try again. During the first burn got to 250', likely need to take it to about 400'. Temp at the cooking grate was 250' at the firebox side and 200' on the other side. Need to come up with a diq baffle to even the temp out. The chimney extension has been a pain because the 3" dryer vent does not fit well. How about you? The grill side gets very hot very fast! Almost too hot. Very hard to keep the temp low. Looses heat fast when opening the lid.
Still breaking it in and getting the feel but so far but I'm pretty happy with it.

Smoker Side:

I got it together, smoked some bologna on it just to get an idea what it was like stock out of the box, and then went on vacation last weekend and haven't had a chance to smoke anything else. The bologna actually turned out very well considering the leaks and temp spikes due to my poor fire management.

I did use food safe high temp RTV to seal up the fire box seams, though I didn't have much smoke leaking there that I could see. Seasoning probably would have taken care of it but it didn't hurt anything to seal it. I let it cure while I was gone four days on vacation then covered it with high temp black paint when I got back home.

My main smoke loss is around the smoke box and chamber doors which was expected.

I bought nomex gasket and installed it but it actually made the gaps worse so I'm going to have to play with it some more when I smoke this weekend. I split it in half by width so that it would fit on the lip of the chamber. I'm still trying to decide if I want to play with gasket arrangement or just install clamps like so many others have to pull it down into the gasket to seal. I'm leaning toward the clamps right now.

I also took some of the nomex gasket and sealed the gap between the smoker body and the external stack which looks to have closed it up tight. I'll see when I put some more smoke through it Sunday.

With a couple of small hickory splits burning on a good bed of coals I was running ~300 on the firebox side and ~250 opposite. One split was about 250 and 200 like the temps you saw.  I'm happy with that stock out of the box considering I'm horribly out of practice with regards to fire control.

I'm still working out the idea of a baffle too. It's going to need something to even it out since the chamber is small.

I haven't lowered the chimney and I'm not sure I will. Smoke was doing a pretty good job of filling the entire chamber but we'll see how it goes.

I'm using the charcoal grate and plate that is supposed to be in the smoker chamber in the smoke box for easier clean up. I'll use the plain grate in the chamber as a stand for drip pans and such. I can't imagine I'll ever use it as a straight up charcoal grill but who knows. If I do the grate is easy to move.

Grill Side:

Holy surface of the sun hot grates, Batman. It will flat out sear a nice steak.

It heats up extremely quickly. Even on the lowest dial setting it sits pretty comfortably at 400 degrees on the grate (per the Maverick) with the lid closed. Lid therm reads 450. It does seem to lose heat quickly when you open the lid on the grill side but it recovers so quickly it doesn't matter much.I expect it will settle itself a bit once it is better seasoned. 

Overall:

For the price I'm really surprised how nice the materials are and how good the fit and finish is. All the seams sucked up super tight when assembled and every bolt and screw hole lined up perfectly. The metal is approx 1/8 inch thick through out and it's very solid. They even powder coated the wood rack which is a nice touch.

The grates aren't the best I've ever used but they are much better than the normal smoker/grill grates you get at this price range.

I had 2 very small (less than 1/4 inch long by 1/8 inch wide) scuffs or production/handling marks (leaning toward this since they're in the same spot, one centered behind each door on the rear of the drum) that I covered with high temp paint.

I hate the metal wheels. At some point I'll replace them with rubber like someone else here did. It should make moving it much easier, as well as quieter. For now though they serve their purpose.
 
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Thanks for the quick response. I forgot to mention that I also used nomex on the smoke door. I kept it full width. It also worked somewhat but will require some tinkering. I actually have less gapping on the smoke box lid but the gap around the smoke inlet is not impressive. Not quite sure how I intend to deal with that.

I would have to say that the materials are of good quality however the fit and finish is not what I had hoped for. But I guess that's why they are called COS. The Steel wheels are a nice back country look but not so hot for mobility. I don't plan to move it much but if I do a couple of flotation tires are in order. I also plan to have my son weld up a charcoal basket as many have suggested.  Since I do enjoy trying to turn a sow's ear into a silk purse it fits the bill. my first smoke will be a cold smoke with cheese using an A-Maz-N tube smoker. Let you know how it turns out.

BTW, If you come up with a good idea for the chimney extension please let me know! I don't get any leakage but it needs to be extended to the grates. Grates, yeah I don't think they will last long. I think some heavy gauge expanded metal in a welded frame may be in order.
 
I was talking to a coworker last week about baffles and showed him a pic of the LavaLock model on bbqsmokermods. This is the coworker everyone has who eats meals that people brings but never brings a contribution to the meal.

He showed up yesterday with an 1/8 stainless steel sheet and offered his metalworking shop if I needed tools to make myself one. I guess being nice comes around now and then.
 
Well, just goes to show that when you least expect it, something good happens!  Just a bit of an update: First smoke was actually ribs. Had some trouble maintaining 225. I wanted to hover around 235 and I did add additional charcoal but to late so temp went down for about 15 minutes to about 215. Anyway took the ribs off after 3hrs and they were not done completely so popped them into foil with a 7up and finished off at 225 for 2hrs. Turned out good. Next time I will try to control the heat better. Second real smoke was with AMAZN Tube smoker and cheese. This worked much better since I did not need to control the heat. Cheese went 2hrs and turned out great!
 
Sorry I have not replied but I just got back to the forum. I will check tomorrow and maybe send a pic.
 
OK, I finally got out and measured the baffle's I use on the SJ Longhorn smoker side. Truth be told I have not been very successful with hot smoking. Ribs only and those needed finishing in the oven:( But cold smoked cheese is GREAT!

The angled baffle is ~ 19" x 7 1/4". It is about 3" on the vertical side attached to the fire box/smoker wall. It is held on by the four bolts. The angled portion that extends down and into the smoke box chamber is about 4 1/8". The extra 1/8" is taken up with the angle bend. I did not have a welder or the final dimensions to go pro so I bought an aluminum tray from wally world and cut it up with an angle grinder. The second piece is horizontal piece from HD and measures 18" x 6. The 18" is just right to span the bottom and will be your guide for the angled baffle. I usually leave a gap of 1/2 to 3/4". I also had my son weld charcoal basket 13 3/4" x 12" x 6" with pieces from HD. I apologize for not being more diligent in responding. I know how frustrating it can be when you need info.

BTW I just got a Mavrick 732 thermometer to better monitor the grate temp so may be I won't have to finish things in the oven. If you have any additional questions I'll try to be quicker!
 
Looking to mod a Oklahoma highland planning on doing some mods like wielding firebox to main chamber and moving smoke stack to other side to make it reverse flow ANY and all tips are appreciated
 
Not sure if yours is the CharBroil vintage but if so I don't know if the metal would stand up to welding.
 
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