anyone here build a flat top griddle?

Discussion in 'Grilling Tips' started by lightfoot, Nov 3, 2011.

  1. I recently picked up a 3 foot wide X 18 inches deep- commercial flat cooking griddle on a stainless steel table at an auction for cheap ($76). It's stainless, 5/8 inch plate. It was electric at one time (didn't work) but i removed all the heating elements and controls and am replacing them with propane burners, in order to make the unit portable. I have a pretty good idea how i'm gonna locate the controls and such, but i'm wondering how close to the bottom of the plate i need to position the propane burners in order to get the best even heat. I've Googled till i'm cross-eyed and can't seem to locate any info. has anyone done this, or have a griddle they could look at and give me an idea? If not, i guess i'll just make them adjustable till i find the best location before i lock them down. It's a winter project, but i'm ready to get started on it now and was hoping i could get some info here. I finally got all the baked on grease off of everything (what a job!) and now am ready to start assembly. The unit is probably 20 years old or more but in great shape once i got all the crud off. I can post pix later today if it helps, but i'm just looking for a starting point to locate the burners. I am thinking of going with 3 H-shape burners to give me "zone control".  I'm thinkin about 3-4 inches, but any thoughts on how far below the plate to mount them?

    Or, do i just worry too much, and the location shouldn't matter?

    Mods-if you think i might get more responses in another section-Please move this post
    Last edited: Nov 3, 2011
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

  3. The flame should just roll off the bottom of the grill a 1/4-1/2 inch when on high.  Depending how many burners you have air flow could pose a problem. This will dramatically effect your flame color and size. Also most electric grills don't have the flue to remove spent gas.  Zone control will need to be accomplished with thermostats.  The norm are BJ stats.  They modulate down when the set temp is being reach.  Please post your pics.
  4. Thanks for the replies so far!


        I'm afraid pix wouldn't do much good at this point (it's entirely in pieces, scattered all over my shop), but i'll try and get some on here in the next couple o days.  I have the entire unit dis-assembled as far as it can go right now.  I was just gonna do the outside parts but decided to do it right, and tear it (and the stainless table it came on) as far down as i could and start back clean. No two pieces of anything are bolted together right now.  I even have the griddle plate upside down on some sawhorses cleaning it.  I have been cleaning all the parts (including the table pieces) with mean green, vinegar, and steel wool pads.  This thing will be like new when it's done.

        The griddle cabinet does actually already have a row of vent holes/slots at the back for venting and i can add more if needed.  I have decided against any thermostats and will regulate the flame/heat with burner controls from a three burner propane gas grill i hope to be cannibalizing soon. I ran in to a friend of mine yesterday, was telling him about my project, and he told me to come by his house-he had already done it.  Only thing is-he used a single burner from a large set of gas logs, but that doesn't enable him to zone heat, and it also does not put out uniform flames like gas grill burners do. I plan to have at least two, maybe three h-shaped grill burners. His burner was mounted about 6 inches below the griddle, but the flames were at different heights along the burner  (i guess thats the way it was made to make the logs look realistic).  Also the flames were not all blue like the grill burners will be, which is hotter flame. I'm thinkin just from looking at his, i'll try it at about 4 inches below, and i will make them adjustable (at least temporarily) where i can move them up some if i need to (and i think i will probably end up somewhere at between 2.5 and 3 inches-just guessing.  According to everything i've read, the hottest part of the flame is right at the tip, so i'll end up putting the burner in, turning it on high and adjust from there to get the flame tip right at (or on) the bottom of the plate.  Low flame would obviously not reach nearly as high, hopefully giving me the zone control i'm looking for, from burner to burner across the plate.

    It may work, it may not, but i have all winter to figure it out.  I really wanna stay away from thermostats if i can, and make operation as simple as possible (and also trying not to spend any more than i have to-i'm cheap like that)

       I will try and get some pix as soon as i get everything cleaned and start putting it back together.  I wish i woulda got some before i started, but i was so excited to get started, i forgot.

    Thanks again for the replies, and i will post pix of the progress.
    Last edited: Nov 6, 2011
  5. Something else to consider is that most commercial hibachi grills keep the heat primarily in the center of the surface.  This serves two purposes.  First, the centralized heat creates a downward bow in the stainless (this goes away when it cools back down), which keeps the liquids in the center of the grilling surface with the food, rather than running away and over the edges.  Second, it allows cooler zones on the edges to move food when it's done. 
  6. Are you going to have a common manifold?  If you do then I would suggest at least going with a manual burner valve.  One for each burner.  These run about $6.00 and this way you will have some control over the grill and they would give you the orifice to slip the burner over them.  You would need a 1 1/4 pipe then tap it where you want the valves to go.  Your going to want one burner for every foot of grill. Take a look at this breakdown of a very basic commercial grill. AmerRange.pdf
  7. That's the way my buddy's is, with the hot spot in one area-the length of the burner.  Mine has 3 inch stainless splash guard sides and back, and a 3 inch grease trough with scrape hole in the front.  I'm hoping by putting in 3 burners, i'll have considerably more temperature control rather than just having one hot spot.  I'd really like to have three zones, so i could leave one off if i wanted to, have a place for onions, toppings and such, and a place to grill burgers, or light the whole thing and grill burgers on all of it if i wanna.  This is actually the first step for a backyard outdoor kitchen i've been wanting for a long, long time.
  8. Very good info! I really appreciate your time.

    That's what i was kind of thinking, 3 burners-i per foot would work perfect.

    and thanks for the link!

    have you ordered from these people before?
    Last edited: Nov 6, 2011
  9. I have a small commercial appliance repair business for the last 20 years.  We buy wholesale.  They are a retail outfit mostly selling to fast food chains. Tell me what size burners you are looking for and maybe I can find some old ones in the shop.
    kydave likes this.

  10. EJ,

    I just did some measuring, and if the burners are U-shaped (like in the drawing you linked), i think 12 inch (length) ones would work and give me a little play room to adjust them forward or back and side to side to get even coverage.

    Will the fact that i'm using propane have any bearing on what type burners i need, or just the orifices?

     I'm learning as i go, so can i order the manual burner valves from Whaley and just get 1 1/4 black pipe and tap it at each location?  I really appreciate your help, and will gladly pay for the burners, shipping, and your time.

     I'll try and get some pix up later today of the bottom of the unit with the griddle setting on the cabinet.
    Last edited: Nov 7, 2011
  11. ok, heres the pix, for what it's worth

    hope this works

    remember, the cabinet is sitting upside down on the griddle.  the slotted panel is the back side of the griddle cabinet- (and aluminum if i need more openings for air flow-easily cut).

    The rest of the cabinet is stainless.
    Last edited: Nov 7, 2011
  12. Just propane hood orifices will need to be used.  You are going to have a major problem with air flow.  Your grill is enclosed because it was electric, it didn't need it.  You have no flue in the back to expel the exhaust.  You will need to fabricate one or cut off the upper portion of the back.  You will not be able to place it against a wall.  It would catch fire.  Your front panel is all wrong.  Your valves need to be set up directly behind the burners.  Also with air intakes directly in front.  Look at the pdf file to see what I mean.  Also almost all griddle burners are going to be 24" in length. 
  13. EJ,

    thanks for all the input!

    fabricating a flue would be something i could do, no problem, and i will plan on it, thanks!  The back is aluminum so it cuts much easier than the rest of the cabinet which is stainless.

    It won't be placed against a wall, or used indoors at all, it's for an outdoor cooking patio area in the works.  Actually i will likely put wheels on the stainless table that came with it and just roll it in and out of my shop.  

    The front panel, i can completely re-do.  I kinda figured the hole locations were all wrong for what i'm trying to do, so the entire front section may need to be cut out and a new panel bolted on over it.

    I really appreciate your knowledge, which will no doubt save me a lot of time.

     If you say the griddle burners are usually 24 inch, then i guess i'm back to looking for a gas grill to cannibalize for the controls, and i can buy 12 inch H-shaped burners for grills locally for about 10 bucks each, which will give me three separate heat zones.

    I have been studying that pdf file you linked and have gotten a lot of ideas from that drawing, and your knowledge.  I can't tell you how much i appreciate it!

    I will post pix as this project begins to take shape, and if you don't mind, i'll likely be pm'ing you for some more info.

    thanks again

    Last edited: Nov 7, 2011
  14. I've thought of making one of these as well.  I have the parts for a smoothtop stove (without the top, because it got smashed in shipping).  I got refunded my money, and was told just to dispose of the remaining parts, but I kept them (naturally).  I was also thinking of using them for an electric smoker, but I have been struggling with the concept a bit, and my wife thought a Japanese-style grill might be fun.  I need to find a nice peice of thick stainless, though.

    You can see a picture of the parts I have in this thread:
  15. Lightfoot what are the dimensions of your flat top?  12" burners are tiny for and commercial grill.  Normally the burner coverage will contact the grill top form front to back.
  16. There is a place in Nashville, Tn., called KG Machine that can make a griddle plate any size you want, any thickness.  I spoke with Chris there a time or two before i found mine, i was thinking of having them make one for me.  Very nice people!
  17. EJ,

    my griddle is 18d x 36w.  I was thinking of running the 3 H-style burners side by side.

     My thinking on this,

    12 inch burners would would fit front to back with more room than i wanted to spare, but i had thought about putting them closer to the back because i won't be using the front few inches next to the grease trough likely anyway.  If i have to sacrifice any surface due to burner size, i'd rather it be there.  I know it's not perfect, but this unit wasn't designed to be gas, and i'm making a gas griddle out of it, so i can't expect it to be perfect.  (It will be good enough for who it's for) lol.

    They would also fit side by side ( i found some that were 9 inches wide ) and was thinking a couple of inches between the burners at least, which would work out about right width wise.

    From looking around, i found the longer the H burners are, the wider they are too (at least the ones i've seen so far have been) and i like the idea of having three heat zones, which is why i'm willing to sacrifice a couple inches on the front if i have to.  I'm still looking locally for burners that will work better, but so far that's what i've found.

    let me know what you think, I've not bought anything yet and

    i'm still open for suggestions!
    Last edited: Nov 7, 2011
  18. Go take some pics of the burners and closeups of the air shutter part so we can see how best to adapt them.
  19. Ej,

    thanks for the info.  I really appreciate it!

    But, i putting off buying any burners or anything just yet.  There is a gas griddle coming up at an auction in about a week and i'm gonna try and get it.  That would be much easier to do (switch to propane) than to completely build one from the tank up.  That may be what i end up doing, but i hope to get this one and sell the current one to my B.I.L.  I'll let ya know as soon as the auction is over.

    thanks again!
  20. I think you would have a better usable grill that way.  Good luck.

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