Hotplate stainless steel and prep

admin

Hi all,I want to install a hotplate into a counter but what I need to know is the correct stainless steel type to use for food prep. So far my investigations result in 304 or 316 being recommended.My counter has a rebar/concrete inner with decorative tile outer. I want to cut a hole in the top to insert the hotplate. An initial design for the hotplate are below. It measures 20" x 12".I would really appreciate any help with the following:Is the grade of ss above correct for this application?What thickness would be good to hold up to cooking temperatures and cycling?Would a central support be required to prevent warping?TIG welding all joints and I am assuming stringers to prevent catch points for food/cleaning materials?What kind of surface prep would I need to do before first cook?Thanks for any pointers...
Reply:Either grade is fine, 304 is normal for cutlery, 316 is special marine grade. There is also 321 for high heat. Angles on the back would help with warping, or use thicker plate. There will be some oil on the surface of the steel, can be removed with soap.I'm curious what the heat source is. The design is not complete, you need tabs to hold the plate up?Keep us posted.SqWave 200Millermatic 190Airco 200 ACHypertherm PM45Boice-Crane Band SawVictor O/A
Reply:I can't help you much on food grade stainless, but I've done a few concrete counter tops over the years. Be careful when you go to cut one. Depending how it was made and supported, those sharp corners may give you issues when you go to cut it. You may give the concrete a perfect place to want top crack. Also many times ends of a counter are cantilevered and once you cut thru the steel and now are just supporting the top off 2 narrow areas you ca ask for things to want to shift..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Thanks guys, my plan is to weld the flat plate to the angle around the seam so there will be a step down from the angle to the plate by about 1-2mm. The angle will then drop into the hole and covers the rough edge left in the concrete. Makes it removable if needed.Not decided whether to go with gas burner or IR as the heat source. Need ventilation underneath either way.
Reply:The counter was fabricated with the frame just like a steel tube table so cutting a top hole will not cause any structural problems, just some cut tiles. Checked and confirmed today.
Reply:T304--and food equipment is what we do.  The other grades only come up for specialty needs.Because T304 is a bit expensive and some fabricators are cheapscates (chasing China cheap),  you may also find a lot of T201 these days in commercial stuff.  T201 basically replaces expensive nickel with molybdenum,  Not really relevant to your need right now but just warning people that they need to be aware of that issue in case they have to weld on someone else's equipment.  T201 can be far more brittle under certain circumstances than T304..like welds cracking.When you say "Hot plate" do you mean warming plate or actual heating surface?  You don't really want T304 to sit at temps between about 600 f and 1200 f in oxygen environments due to "green rot" potentials...plus it'll discolor.  Not a huge deal in most cases but other alloys might be a better choice if you are talking high temps.When you start buying stainless in plate thickness rather than sheet, it's harder to get stuff with smooth surface textures--it tends to look grainy.  You might want to specify a 2B or better finish and stick to sheet gauges if you can't examine the part before you purchase (http://www.ssina.com/finishes/sheetsamples.html)Last edited by Kozmo; 12-26-2014 at 01:50 PM.
Reply:Thanks for the link, very informative.I have found 1/4" 304 locally and as you say the surface finish is grainy. The surface will be used for direct cooking and I am leaning towards using an open gas burner.
Reply:Originally Posted by negativ3Thanks for the link, very informative.I have found 1/4" 304 locally and as you say the surface finish is grainy. The surface will be used for direct cooking and I am leaning towards using an open gas burner.
Reply:You are calling this a hotplate...do you plan to 'just keep things warm' with it, or actually cook with it?  If you are going to cook with it, you need to build a grease tray/trap into this (I can give you more details, if this is the direction you are going).  If you are truly just using it as a 'buffet,' to keep food warm, once it is cooked, then your design is OK.  Is this a home installation, or a professional (serving food for money) installation?  That will make a difference too.KevKevin / Machine_Punk from The Aerodrome Studio - Lincoln PowerMIG 210 MP - Meco N Midget w/custom welding station - Vintage Victor 100Current Projects: The Aerodrome Studio
Reply:With an open gas burner you are also going to need venting and containment for the flame. It would need a fire box and a vent in the back. This is outdoors, I assume.
Reply:Thanks guys,Yes, this will be an outdoors setup for home use only and it will be used for cooking. A grease trap will be needed and some sort of fume extraction was in my plan a little further down the road, after getting materials sorted out.Walker, I would appreciate a little more info on the fire box you mentioned?This whole idea is based on Teppanyaki stations in Japanese restaurants.
Reply:Might just google a commercial griddle and look at some pics. Basically , if you put in some tube type burners, or any burner, they need to be surrounded on all sides with metal to contain the fire. if you don't you will ignite things with only the radiant heat, or possibly when the ignition delays, or the vent gets plugged. it would need to have air intake vents that are covered with a stand off plate as well. Take a look at the griddle in this link. there are some drawings as well. the box below the griddle is the fire box, and the lip in the back is the full length vent. these are usually under a vent hood to handle the exhaust. http://restauranttory.com/imperial-c...-imga72281.asp  They also make electric griddles. You might be better off buying the replacement elements and thermostat and just drill and tap some blind holes into the bottom for retainers. still needs a fire box, but easier to make.