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Rust on smoker

Laxdfns

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Alright, I'm underway on my restore of my new to me Tejas. Some questions: the top of the firebox here has been wire brushed and then hit with a sand flat on and angle grinder and 40 grit sandpaper. Its pitted quite a bit, and the metal isnt the new metalic shiny, and I'm not sure I could get it to that unless I had a grinding disk, but that seems like it might be more trouble than I'm trying to do. My main goal is to prevent further rusting and get it back to nice and black, and for that I have paint and primer.

My question is do I need to sand this more, and/or treat it with any chemicals to prevent the pitting/rust from rusting further before painting it? Or is it kind of a lost cause since the rust has already penetrated the metal?
 

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mike243

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They make some stuff to put on it that will convert the rust to something harmless, then you can paint. cant remember the name
 

thirdeye

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The problem with sanding or wire wheeling is that you don't have the right 'profile' (or roughness) of the steel for the primer to adhere to, and sanding can't remove rust in the tight spots. So eventually the paint system will fail. Primer is way more important than the top coat. You really need to get it sandblasted, then make sure everything is dry before a couple coats of hi-temp primer.
 

Laxdfns

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I've got rustoleum 2000 degree primer, and it says it "stops rust".
Sandblasting unfortunately is cost prohibitive, so would I need to get something like rust reformer first and then primer, or would I probably be ok with this primer as is?
 

chopsaw

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Get a couple sanding sponges in the paint dept at a big box store .
Wire brushing can cause more rust to form .
 

SecondHandSmoker

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Give it a wipe down with solvent or alcohol and see what it looks like after.
You've already knocked off the loose flakey stuff.
You have a few options for the pitting:
1) Attempt to encapsulate the pitting with repeated coats of hi temp primer followed by sanding after each coat. Follow the directions on the primer as some hi temp primers require a curing at certain temps.
2) More aggressive grinding (36 grit flap disc ) Yes, it will remove a lot of stock if you're not careful. Then follow up with a blending disc. Then a 120 grit finish.
3) Live with it. Sounds like you are leaning toward that anyway. It won't look too shabby with a couple of coats of paint. If anyone asks, tell them it is a "special edition" finish. :emoji_sunglasses:
 

civilsmoker

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Gets some scotch bright pads (red or green) and some grape seed oil (or canola oil) and give the rusted area a good rub down with oil and wipe off the excess oil and rust. Do that three or 4 times and wipe it dry as you can and then build a fire and get it hot till the oil starts smoking and then let it cool. This will season the steel. Then just maintain it each use by rubbing It down with oil.

if you want to paint it, get a gator wheel (for a drill or 4.5 angle grinder) and it will do the job without taking the material. It will probably take 2 or 3 to do the whole unit.
 

1MoreFord

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They make some stuff to put on it that will convert the rust to something harmless, then you can paint. cant remember the name
There are a couple of products that will do this. The only one I can remember is Loctite Extend.

Naval Jelly removes rust. It doesn't convert it.
 

SmokinAl

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I would just spray it with Pam, every time you use it before & after you smoke something. That will keep it from rusting further & season the steel.
Al
 

Laxdfns

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Long update:
Went ahead and primed last night. I thought about not doing it so I could try what you all were saying (gator wheel, rust removal) but quick searches on rust converters, etc all showed them rated at like 200 degrees and my firebox definitely gets hotter than that. Plus didnt want to not have time to seal in everything in case the rust started returning right away. I've heard horror stories it can creep back even overnight.

So I decided to "live" with the pitted finish, I love smooth but honestly I just wanted the thing black again and no longer risk to more rust. Plus now it looks like cast iron, which is kinds cool.

One big difference between myself and the last guy is my smoker will be garage kept. My understanding is he left it outdoors in Wisconsin weather, not sure if he covered it. Hopefully non exposure to the elements, along with coating it with canola after each cook.

Now for another question:
Went through 6 cans of 2000 degree primer, it got me about 2 coats for the cooking portions of the smoker, and 3 for the firebox. Think I should get more? How many coats would be recommended?
 

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thirdeye

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I've got rustoleum 2000 degree primer, and it says it "stops rust".
Sandblasting unfortunately is cost prohibitive, so would I need to get something like rust reformer first and then primer, or would I probably be ok with this primer as is?
Chemical treatments contain phosphoric or hydrochloric acid, then there are rust converters, but the 'primer-like' coating they leave behind doesn't like heat. I use the same primer, let's say it delays rust. Have you checked with local sandblasting contractors for pricing? A couple around here do outdoor blasting on oil field equipment.... so a typical deal is to wait for them to be set-up on a job, then you take your smoker to them and they give it a blast for a minimal fee or a couple cases of beer.

If you do decide to clean and paint without blasting, here is the deal.... primer is the important step you need several thin coats with cure time in between. The most important is the 'stripe coat'. This is an initial coat on all the hard to cover areas like edges, corners, steps, transitions, bolts, welds, weld splatter etc. Spray a light band on these areas only and work it in with a brush, repeat until you get good coverage. Feather the primer onto the bare steel as you spray, then let it cure. Inspect your job, and re-spray any areas that look too thin. Yes, your smoker will look like a zebra, for now. When you are ready to spray the main body go with a light coat first. You need to have something for the next coat to adhere to. Feather into all of your stripe coat areas. This will help hide the additional thickness of paint on the stripe areas. After this, one final coat should give you a good primer job. Then move to the top coat. I like to repeat the stripe coat with my top coat of paint, but if your are careful and take your time you could skip that.
 

thirdeye

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Oops, looks like I was too late with the initial advice on primer. To answer your question from this morning... inspect and apply primer as needed, again its the important layer in any paint system. And don't forget to let the primer cure. Since it's inside, a couple of days might not be out of the question.
 

Laxdfns

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Oops, looks like I was too late with the initial advice on primer. To answer your question from this morning... inspect and apply primer as needed, again its the important layer in any paint system.
It's all good, and you'll be happy to know I primed in your advised manner.

As for the sandblasting, its cost prohibitive not so much because of what theyd charge, but I lack the means to bring the smoker anywhere. I had to rent a truck to get it to my place, and that ended up being like 200 bucks. In any case I went the way I did and I suppose I could always try sandblasting next time!
 

thirdeye

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It's all good, and you'll be happy to know I primed in your advised manner.

As for the sandblasting, its cost prohibitive not so much because of what theyd charge, but I lack the means to bring the smoker anywhere. I had to rent a truck to get it to my place, and that ended up being like 200 bucks. In any case I went the way I did and I suppose I could always try sandblasting next time!
From the time stamps I was typing about the same time you were replying. I'm usually not on the computer this early but I have a brisket going on my pit and there is a light rain, so it's taking longer to come up to temp.

Glad you took time on the primer, and at this point in the game allow as much cure time as possible. You never want to put top coat over non-cured primer. Tomorrow, you could even build a really low fire in the smoker, say 10 briquettes, just enough to let the steel get warm to the touch.
 

Laxdfns

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From the time stamps I was typing about the same time you were replying. I'm usually not on the computer this early but I have a brisket going on my pit and there is a light rain, so it's taking longer to come up to temp.

Glad you took time on the primer, and at this point in the game allow as much cure time as possible. You never want to put top coat over non-cured primer. Tomorrow, you could even build a really low fire in the smoker, say 10 briquettes, just enough to let the steel get warm to the touch.
That's the first time I've heard about heating up the primer before applying the top coat, interesting the instructions dont mention it at all. In the past I just primed, dried, topcoats and then cured at 400 or so for about an hour.

So if I've got a pork belly I need to cold smoke for baccon by this upcoming friday, what would you do as far as time frames for priming, painting and the curing for both?
 

SecondHandSmoker

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According to Rustoleum:
"Rust-Oleum Automotive High Heat Primer must go through a heat curing process to properly harden and adhere to the surface. – Bake at 250°F (121°C) for 30 minutes then allow 30 minutes to cool. Bake at 400°F (204°C) for 30 minutes then allow 30 minutes to cool. Bake at 600°F
(315°C) for 30 minutes then allow 30 minutes to cool. Caution: Be sure not to exceed the heat tolerance of the least heat tolerant part. "
 

Laxdfns

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If you want to explore the sandblasting option more, the Harbor Freights unit works quite well. Used a friend's on my trailer frame before painting.
Oh man, that's much cheaper than I had seen. Well, it is what it is, I'm down this path for now, ig the current paint job fails epically, I'll go to this.
 

thirdeye

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That's the first time I've heard about heating up the primer before applying the top coat, interesting the instructions dont mention it at all. In the past I just primed, dried, topcoats and then cured at 400 or so for about an hour.

So if I've got a pork belly I need to cold smoke for baccon by this upcoming friday, what would you do as far as time frames for priming, painting and the curing for both?
You don't want to put steel in the sun or anything, that will cause blistering and let solvents evaporate too fast. Outdoors with a tent (or shade) is okay, plus a little wind helps too. Commercial painting and coating companies have heaters for buckets and barrels, not only will they shoot warm paint, but the paint booth is heated and has circulating air. You can do small localized jobs with a weed burner if you are very careful and apply heat from the opposite side you are painting.... but a small charcoal fire is a low soaking heat.

Cold smoking (if you are keeping the smoker <100°) is not going to harm the primer. You want a lot of draft, so I doubt you would even stain the area around your stack. I'd get your bacon out of the way and shoot your top coat next week. If you put the rattle cans in the sun (or in warm water) for 30 minutes that will help too. And, shake, shake, and shake that can for 4 or 5 minutes.
 
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