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I’m just wondering…..

What other types of heating elements (besides mica strip heaters) are using for ovens?  (John Freedy)

On the suggestion from M-D, I picked up a couple of 850 watt, 110 volt replacement oven elements from McMaster-Carr.  They come to you straight, if you need to bend the elements, you need to bend them before they are heated up the first time.  They work great.  You can mount them with home made standoffs made out of sheet metal and wire.  (Mark Wendt)

Do you have the # for those heating elements?  (John Cole)

Yup.  The item number is 3540K37 on McMaster-Carr web site.  It's listed on the Cartridge Heaters and Heating Elements page.  They go for $28.74 each.  I've got two of them wired up in my oven, with a fan blowing air through a duct, which is right behind them in the box.  I can keep the door of the oven open if I wish, and the combination of the heating elements, the PID controller, and the fan, will keep the oven temperature stable within a degree.  Check out the oven here.  I've got some construction photos that show how the oven was built.  I got the ideas from both M-D, and Don Andersen's plans on the Rodmakers site.  (Mark Wendt)

I can't figure out the air flow.  Fan pulls air in from the outside at the lower right back (standing facing the little door with wood handle), blows it over the  heating elements laying on the bottom, right side, but then where does the air go?  (Claude Freaner)

Airflow is just circular within the oven.  It's basically a home made convection oven, just on a slightly larger scale than the one you'd cook your chickens in...  It blows the air over the elements, around the front inside of the box (all four corners have curved pieces of sheet metal to smoothen and direct the air flow, down through the rod section chamber, around the back side, through the fan and ducting again, and so on.  It creates a highly stable temperature chamber on both sides of the oven, and with the PID controller, holds the temperature within 1 degree of the controller setting.  Opening and closing the door seems to have very little effect on the temperature of the oven, I think in part because of the amount of insulation and also, in a big part, to the PID controller.  When I open the door of the oven, I can feel very little air movement at the mouth of the opening, but the air is moving at a pretty good clip inside the oven.  I'm not exactly sure what the pitch of the fan blade is, but it's a 10 blade, 5" diameter fan, that's being turned by a 1/4 horse fan motor at if I remember correctly, 3450 rpm.  There's a 2" pulley on the fan motor, and a 3 1/2" pulley on the fan shaft.  All in all, it moves quite a bit of air in the oven.    (Mark Wendt)

I called McMaster-Carr today because I couldn't find these elements in their catalog.  I asked them if they have them in stock and they told me that they don't have them any more.  What is the part number for these elements so I can call them again to find out if they still have them.  (Robert Holder)

Check out McMaster-Carr part # 3450K37, I think this is what you are looking for.  It’s a 40in 850w 120V bendable heating element for $28.  You can control it with a common dimmer switch found at HD.  I pulled the heater element out of a discarded dishwasher and used the dimmer with it.  Works pretty well, but the addition of a fan would make it more effective.  I hope Mark can provide more details on his fan, how to install it, how it is ducted, etc.   [;)]    (Kyle Druey)

I've made a couple of these ovens. Have pictures + details are on Rodmakers. Need pictures of ducting etc., give a shout.  (Don Andersen)

'Tis true.  Don's project was the original inspiration for mine.  I used his drawings and parts to craft my oven.   Thanks Don!  (Mark Wendt)

This weekend my wife and I went on an appliance binge and replaced our 20+ year old dish washer and oven.  So, now I am faced with a couple of potential heat treating oven elements.  However, before I kill myself with this project, thought I might ask a couple of questions.

For those of you who have used these things, how do you wire them up.  As near as I can tell, they both use a similar element.  Both units are GE, and the elements are the plug in type (using a receptacle).  Of course, the oven runs on 240 while the dishwasher runs on 120.  However, does the dishwasher element get hot enough to heat my oven to 375?  And can it be re-bent to fit my oven cabinet?  I know that oven elements cannot be reshaped, but I'm not sure about dishwasher elements.  Seems like it should be OK if I don't crack anything.

As far as the oven is concerned, I can get a couple of new elements on eBay (they are not straight either, but as I understand things, they can be straightened before they are heated, right?) for about $10.  Can the receptacles be rewired to use 120v?   If I have to wire the thing to 240,  I don't  want  to use it.  I only have one 240 circuit in my shop, and that is for the table saw.  I know there are at least a few people who have used stove or oven elements for their ovens.   How did you wire them up, since none of those things come with plugs directly attached.

So, anyway, are there any suggestions?  I like the idea of using my oven parts since I can get the thermostat and such.  Seems like I might be able to control it better.  However, the dishwasher is already set up to run on 120v.  What do you guys think?  (Jason Swan)

BTW, I should mention that I am trying to find the best solution for doing this on the cheap.  Under $100.  So, now that I have the parts, seems like a good idea.  All I need to do is build the cabinet and install the fan and motor I have been saving, etc...

240 Volt (Oven) elements can be wired and used on 120 Volts.  However, they will only run at one quarter of their wattage.  So check the wattage of the oven element. I have checked into this because I have a 5000W 240V electric element that I plan to use for my oven and I know that It will only consume 1250 Watts on 120 Volts. As this is over most of the Mica Strip elements used for ovens, I have not concern.

Since you are looking at buying a new oven element, why not try bending the old oven element to straighten it out?  Can't you retrieve the receptacle for the element from the oven? Other elements have either screw terminals or 1/4" quick connect terminals for connection of the wires. Just wire the the receptacles for 120 Volts.  One side to the HOT leg (Black) and one side to the Neutral leg (White).

I don't know what the wattage of the dishwasher element is, but it may be enough to do the job if it can be straightened out.  The oven element is probably 4500 Watts so it would be just over 1000 Watts on 120 Volts.  (Dick Fuhrman)

In my poking around the archives etc. in the last year I have come across considerable material about bamboo ovens all of which is enticing, but I haven't built yet because I haven't made my final decision.  One of the approaches I have been thinking about experimenting with is to try to retrofit a small electric heater I have to do the job.

I have this small heater about seven by seven by ten deep with an electric coil, thermostat, and fan built into it and I was wondering it could be reworked for our purposes.  I didn't find any approach like this in my research and wondered if any of you would like to comment on the idea?  I almost think I could mount it in one end of an insulated ductwork box similar to the way we use heat guns.  (Dick Steinbach)

Depending on the wattage of the heater you may be able to generate the temperatures needed or you may just have to adjust your tempering times for a lower temperature.  If you have been researching the archives you have probably read about the importance of circulation for preventing hot spots. I did about the same thing with my oven but I also use a coiled heat element due to the fact that the heater would only bring the temperature up to 190 degrees.  On it’s own the heater is perfect for curing glued sections.  My oven works OK, but I do have some problems with temperature difference of around 7 degrees from end to end.  I’m going to rebuild it this winter and try to produce a simple recirculating system.  (John Freedy)

I built a recirculating oven with a 1000 watt heater in the return loop and have a fan moving about 600 CFM through the 10 inch diameter oven chamber. All well insulated with fiberglass and I still have an end to end difference of about 5 degrees.  All this tells us is that to achieve no temperature difference you need infinite air movement or infinite insulation.

Just some info for when you build or rebuild.  BTW, I’d say a 1000 watts is just about right to get the oven up to temp in a reasonable time (less than an hour to 350).  (Al Baldauski)

I doubt if any oven operating at or above 350 degrees F would produce an even temperature throughout the unit. However, 5 degrees is within 1.5%; so, congratulations. I think that is well within the accuracy that we can achieve working with bamboo and various glues and hand plans and all the variables that we encounter in our craft.  However, let me say that a well insulated vertical heat gun oven will bring the temperature up to 375 within 10 minutes.  (Lee Koeser)

Your heat gun may well be in excess of a 1000 watt and if your oven size (total surface area) is much less than mine then you’ll get it up quicker! I haven’t timed my rise so it may be well under an hour.  (Al Baldauski)

According to what I have learned, my little heater is 1500 watts so I guess it should do it.  Robert Holders sent me some great pictures of one he is building and I think I can reproduce it. Also I have a new 1500 watt heat gun  that I bought for this  purpose so I'll just have to experiment with both to see what happens.   (Dick Steinbach)

With my vertical oven, I couldn't bring it up above 325 degrees F.  The oven wasn't insulated and the heat gun was a 1200 W device. 

I wrapped my oven with insulation (fiberglass with foil backing - facing outward) and bought a 1800 W heat gun and now the oven cranks up to 400 degrees F without any effort and within 5 minutes or so. 

It's nice to also have an infinite heat setting and a high/low setting on the heat gun.  Also, removing the oven "lid" helps regulate the temperature. I just finished cooking a friend's rod.  They baked  at 350 degrees F for 9 minutes for the tips (which have a taper to them already) and at 350 degrees F for 12 minutes for the butt section.  (Scott Turner)

Has anyone come up with a cheaper alternative to a mica strip heating element for their ovens? Checked the archives but didn't find much. If not, what's the best price and outlet found for the mica strips?  (Wayne Kifer)

I recall a post some time back where a list member took an electric stove apart and bent the heating elements into the proper shape. They even used the stove controller for adjusting temps. There was also a story about a portable electric heater from Walmart that had a coiled element that was bendable.

I use a VERY sophisticated oven system. A horizontal copper pipe suspended by two chains. One end is capped, the other has a threaded thing with a removable cap that has a tiny pinhole. Put the cane in and heat the pipe with a blowtorch while rotating it with a gloved hand. Steam will fly out the pin hole, then the steam plume will sort of taper off, and the smell will change from "wet" to "oily". Cane is done. The idea is right from Garrison, but the smell test is from Bob Nunley.

Just don't put your nose right on the pipe.  (Jeff Schaeffer)

My Heating element is a open coil water heater Made by Camco for the RV industry total cost $14.75 because I use the big 120 Volt 2000W but you could go lower I believe. I have this in a double chamber unit I built out of 8 Inch stove pipe over 6 inch packed with insulation then boxed and packed again. As noted power is run from a 120 vote source through a rheostat for heat setting. A home built motor fan combination sets behind this unit also enclosed in the pipe and forces air. Drying rack is centered and I get very little degree change for up to 6 feet ( I still turn the sticks around half way through the time desired just because I have done it for so many years.  (Ronnie Rees)

I used a hot plate element that I straightened out and reused the control for it for several years, it worked fine. I took a piece of string the length of the inside of my oven to Walmart with me and laid it out on the coil of several hot plates until I found one close to the full length of my oven, I think it only missed 5' by a few inches at each end. One thing, it needs to be a new hot plate,  according to urban legend, used elements won't straighten, who am I to argue <g>?  (John Channer)

In my search for heating elements I came across this site. Thought some in the group might find it interesting. Minimum order is $25 but a group order might produce an inexpensive alternative to Mica strips. I have e-mailed them with typical oven dimensions for recommendations.   (Wayne Kifer)

So I just finished my new oven.  I used a tubular element that I bent in half (more or less with a 2" radius bend).  I attached the element to a Chromalox temp controller with a J style thermocouple.  Mounted the element inside a 5" by 8" box and installed a sheet metal divider with 6" open on both ends of the 5' box.  I put a raised expanded metal platform on the other side of the divider to support my sticks.  I insulated the box with heater duct insulation and inserted the whole thing into another metal box that is 7" X 10".  Capped both ends of the boxes and mounted a heater fan from a bathroom fan/heater unit on the end opposite the door where I insert the bamboo.  The fan is position so that it blows across the elements.

So, I hope y'all have the picture.  I wanted to get into something that has a little more control and a little less hassle for treating my bamboo.  The only problem is that I end up with a 50-80 degree difference between the far end and the close end of the bamboo side of the oven!  Apparently the air blows across the element and as it turns the curve at the far end of the baffle the air temp drops 50 to 80 degrees in a space of about 3'.

I would sure appreciate it if anyone has a suggestion for improving my design.  I thought I was doing what most of y'all have done in designing the oven.  Heat on one side and bamboo on the other side of a long baffle to protect the bamboo from the direct heat of the element.  However, I am stumped by the temperature difference.  Any ideas?

I did check my thermometers  (digital thermometers from Walmart).  They both read within 1/10 degree at room temperature.  Could my fan move too much air?  Could the element be to much for the oven?  I bought a 2250 watt tubular thinking bigger is better, right?  How can that logic go wrong?  (Jason Swan)

Most of the fans you describe that I am familiar with don't move much air. How many cfm is this one rated at? It might be that you are only blowing a small amount of hot air into the oven and the temp drop merely reflects the fact that very little hot air is being pumped into a larger mass of cooler air.  (Larry Puckett)

I don't recall exactly.  It isn't the exhaust fan, though.  It was the fan that blows across the heating elements for a warm air dryer in the ceiling. When I installed it we wanted the exhaust and the light, but not the heater, so I took it out.  It blows a pretty good amount of air, though.  When I open the main door of my oven it feels like a hair dryer.  Does that help?  (Jason Swan)

The problem is you don't have enough airflow.  I built my oven with 1200 watts and needed about 700 cubic feet a minute flowing through the oven to achieve less than a 5 degree end to end difference.  And initially, the difference will be greater because the cold end will absorb a lot of heat until it begins to warm and pass some of that heat further on down the oven. So the more airflow the merrier.  I can't be more specific since I don't know what your supplier resources are.  Let's say you would need a minimum of 1000 CFM at about 0.3 inch static pressure and the fan has to be able to survive 350 degree F temperatures.  That pretty much means you need some kind of fan whose motor is mounted external to the oven.

If you have access to McMaster-Carr or Grainger, I can make some specific recommendations.  (Al Baldauski)

I just replied to Larry about this, but I guess it didn't go to the entire list.  The fan is from the heater unit that was a part of the bathroom fan. I didn't want a heater in the fan, so I removed it.  It is much more powerful than the 70 CFM exhaust fan.  It was designed to blow across the coil elements of the heater unit and down into the bathroom.  It consists of a motor (I don't know what rpm, I'll check that later tonight) and a metal barrel-shaped blower wheel.

The whole thing is mounted on the outside of my box with the blower opening in the fan housing matched up with a channel into the oven.  When I opened the door hatch with the oven on and the fan blowing it actually felt like a hair dryer blowing.  At least as powerful air movement as my Grizzly heat gun.  I don't know what that makes in CFM, but it seems to move a lot of air.  (Jason Swan)

You've described a "squirrel cage" blower.  In order to achieve 800 to 1000 cfm the dimensions would have to be about 8" diameter x 4" wide.  I suspect your blower is smaller.

This is a rough calculation but based on the temperature difference you mentioned it sounds like you have about 100 CFM blowing through your box.  To achieve a 10 degree difference with 2250 watts, you need 768 CFM.

And don't forget,  it will take quite a while for the temperature to stabilize because you are not JUST heating air.  You're heating all of that steel ducting you made your oven from.  Though 2250 watts should heat your box up in under 15 minutes.

You were right.  You can have too big of a heater if you don't have enough airflow to match.  If you heater is designed for 240 Volts, you could rewire it to operate on 120 Volts and get only 560 watts out of it.  This would take more time to heat your oven but would be more compatible with your blower. You  would have much less temperature difference.  (Al Baldauski)

Whelp, there I go a' thinkin' that all I need is a heat source and a fan.  I didn't even consider that there is some sort of reciprocal relationship

between the two.  Dang!  I guess bigger isn't always better...  Guess it's back to the heat gun oven until I can get this thing to work.  (Jason Swan)

Your metal divider  has little resistance to heat so I suspect that heat transfer thru the metal is causing the loss of temperature. I think that after some time the  temperatures would equalize out. However, it's the temperature that goes into the bamboo side that's critical. You may have to run a higher temperature at the element to achieve what you want at the bamboo.  (Lee Koeser)

Would you suggest removing the baffle?  I ran it for nearly 30 minutes, and it never equalized.  One end recorded 370 degrees while the other end recorded 290.  If I remove the baffle do I risk damaging the bamboo when the element kicks on to maintain the temp?  (Jason Swan)

No, I wouldn't. The heat transfer is not undesirable. The Neunemann heat gun oven separates the bamboo from the direct impact of the gun. But, the gun heats the inner pipe to help maintain a more uniform temperature inside the length of the inner pipe. If  I understand your design you have a similar situation. If your temperature controller is not positioned in the bamboo side off the baffle, it needs to be.  (Lee Koeser)

I'm not sure if your fan is just blowing inside the box creating mixing, of if there is a baffle system.  Does the air travel in a circuit over the heater, then over the splines to be returned to the heater?  (Grayson Davis)

Let me put my 2 cents worth in here. Is your complete fan assembly outside of the oven box? That is what I understood from one of your previous posts. If it is this could be the cause of your heat loss. The blower housing and any duct between the blower housing and the oven needs to be insulated.

What Al was stating is that the motor shaft needs to be long to remove the motor from the heat or the motor needs to be able to tolerate the 350°+ heat or the blower wheel needs to be belt driven. I believe that some of the makers use belt driven blowers so that the motor is removed from the heat.  (Dick Fuhrman)

In a 240 V circuit you have two "hot" legs and a neutral.  If you measure (or connect) between one hot leg and neutral you have 120 Volts.  So, to rewire your circuit, disconnect one hot leg feeding you heater and insulate it or remove it from your controller as well.  To the end of the heater where you just removed the hot leg, connect a wire to neutral and you're done.  If your controller is designed to work directly off of 240V then you may not be using a neutral, but it should be available at your outlet.

Usually your hot legs are BLACK and RED, you neutral is WHITE.  And make sure you have a ground on your system, regardless of voltage (GREEN).  (Al Baldauski)

I'm in the process of collecting parts to build an oven and have thought about making one out of a 8 ft electric wall heater. Has anyone done this and if so how did it come out ?  (Jim Tefft)

An 8' element would make a long oven. Maybe a 4' or 6' Baseboard wall heater would be better. A 5Kw 240V element run on 120V will give about 1.250Kw or 1250 Watts. This would be about right. I don't know if the thermostat on one that comes with a built-in thermostat would work for this application or not. I have not paid much attention to those thermostats. It's a thought on a way to go. If the heating element is brand new and not used, it is possible to bend the element into a "U" or configuration that would work in your oven if the element is too long.   (Dick Fuhrman)

With all this talk about heating elements, I've been wondering if people are trying to use too big of element. I would think if a smaller element (lower wattage) and run it balls to the walls, would be better. It takes some time for the whole element to heat up. Usually the center, or maybe the ends, gets the hottest first and then works towards the ends (or center). Every time a larger element cycles on, the center heats up first and may cycle off before the whole length heats up. So maybe use more and lower wattage elements spread out evenly in the cabinet would create more even temperatures.

Has anyone checked to see if these strip heaters heat up evenly??

I use a heat gun oven, mounted horizontally. It has a rheostat heat setting. I shoot the gun into a smaller tube inside the main tube. It has holes drilled in it to resemble a gas burner. Some one mentioned PID Loop control on a heat gun. Yep this would work, but the fan must run continuously. Basically a forced air oven works the same except it uses return air instead of fresh air. And doesn't the forced air oven pull air across the heat element and blow it into the compartment with the cane? Now with some kind of divider or heat sink the forced air would even out the temperature throughout the oven during the off cycle of the element. Ideally, I think it needs an exhaust duct and a make up air duct to transfer the moisture out of the oven. That's why I think a heat gun oven works so well. A heat gun with a rheostat heat control can help keep the temperature more evenly.  (David Dziadosz)

Check out the pics of my oven on Todd's Tips site.  What you describe below is exactly how my oven operates. Except in my case, the PID controller and the solid state relay turn the heat elements on and off at a rate determined by the controller after it's "learned" what it needs to do for the heat cycle.  (Mark Wendt)

I was looking at all the ovens on Todd's site and after reading a lot of posts about ovens, came up with some observations. Looking at the convection ovens versus the heat gun oven. Would the heat gun ovens with either PID loop control or with a rheostat heat control, with the same cabinet design, get you the same results?? Maybe better? Convection ovens with PID loop control cycle the heat element on/off (probably would work better with an analog signal). Rheostat controlled elements produce a constant temperature. PID control gives you an anticipated heat control. It's still heating up/cooling down, only at a faster rate. You're still moving air across the element and blowing it into the compartment with the bamboo. Where it smooths out the temperature is during the element off cycle, since there is no fresh air intake nor exhaust, it just re-circulates the inside air. When is the moisture transferred outside the cabinet? And how many CFM's are those  fans moving anyway?? They look huge and the way they are driven (pulleys), have to be moving a lot of air. Don't get me wrong PID Loop control is very accurate, but is it necessary for such small cabinets and the amount of time it takes for heat treating?

I think with the same basic cabinet design with a rheostat heat control, with a fresh air intake duct and exhaust duct, definitely NOT 100% outside air, (like with a heat gun), would be ideal. You would have to pay closer attention till it got up to temperature, but would produce constant temperatures for less initial costs. People are easily intimidated to thinking they HAVE TO HAVE a high dollar oven to make a good rod. These convection ovens remind me of the large air handling units in big buildings. Loaded with DDC systems and economizers only smaller.

The oven I would like to build would cost a small fortune and probably won't fit in my shop. I could even use it to heat and cool my shop. It would have DDC controls, economizers, heating and cooling coils, enthalpy  humidity control, and everything else I think it needs!  (David Dziadosz)

Biggest problem to overcome is how do you control the heat gun with the PID controller.  You could switch the heat gun on and off by using a relay, but you lose one of the biggest features of using a heat gun - convective air.  Turn off the heat gun, you turn off the fan that blasts the heated air out.  In order to have effective convection, that air needs to keep moving.

Besides, by the time you've purchased a heat gun, you've spent about the same amount of money it would take to purchase a continuous operation electric motor and the materials to make a working fan for an oven.  Good heat guns that control the output temperature well ain't cheap.  (Mark Wendt)

My first heat gun, I wired a switch to keep the fan running and switched the element on/off. Real easy to do. My Milwaukee with rheostat element control was less than $40. It's lasted for a good long while. I also use it for other heating jobs a well. Do the PID controllers have their own self tune function or do you have to figure out your own parameters?  (David Dziadosz)

The PID controllers usually have both.  I've found the fuzzy logic used in the PID's own tuning is usually a lot closer to what I need, so when the weather changes from hot to cold, or cold to hot, I run a tuning session before I start baking strips.  (Mark Wendt)

In these convection ovens, what wattage elements are used and how many CFM's of air are the fans moving?? And again how about a fresh air intake and exhaust ducts? Please don't take me wrong, I might still build one. I haven't been able to totally justify it, it's just too damned interesting to me to not build one. I have worked with controls for air for quite  a while, now mostly moving water, chilled and/or hot.  (David Dziadosz)

I use two 750 watt elements for a total of 1500 watts.  Not sure what the cfm's are, don't really have an accurate way of measuring that handy.  Nope, no fresh air intake or exhaust duct.  It's a re-circulating convection oven.  The air moves in a closed loop between the fan/heating element chamber to the cane cooking chamber, then back through the fan/heating element chamber, ad infinitum.  (Mark Wendt)

How is the moisture transferred out of the cabinet? I can see how the temperature stays constant, (recirculation). Where did you get your fan/motor? What is it rated for?

Again, I'm NOT TRYING TO be a smart a$$, maybe dumb a$$ is closer! (David Dziadosz)

Couple of ways - open the door for a bit to let the moisture escape, or leave the door closed until the cool down period.  A lot more moisture can be absorbed by the air at elevated temps, so depending on how many sticks you're heat treating, you may or may not have to open the door.  The PID controller does a wunnerful job of keeping the oven within plus or minus 1 degree of the set temp so it doesn't really hurt to open the door,  and when I do open the door, it's usually on the ramp-up to the set temp anyway.  (Mark Wendt)

That doesn't sound like the "High Tech Guy", I thought Mark Wendt was/is or whatever! LOL

Now, at least go out there and cut in a minimum outside air duct. If you draw in more than you exhaust, it will pressurize the cabinet, providing you have some kind of air foil blower, and all the moisture will escape through all(if any) little tiny holes or leaks.  (David Dziadosz)

I have a small wood wedge that I use to hold the oven cap cocked at an angle to have an opening for the moisture to escape. I check this slight opening with a small mirror. When no more moisture appears on the mirror, I know the strips are dry.  (Tony Spezio)

1500 watts! Hell, I probably could heat my little shop of horrors! So, I'm guess you're staging them on? And also, my point of which is, use smaller elements and run them balls to the wall in stages!  (David Dziadosz)

Nope.  Just letting the controller, through the SSR turn them on and off.  KISS...  ;-)  (Mark Wendt)

My heat strip has decided to go south. Where is the  best place to get one.  Ordered one from a Tulsa firm, they could not supply it. Waited a month to find that out.  (Tony Spezio)

Here's a link to Omega Engineering for a 120 v 1250 watt strip heater in stock.

I've dealt with them as a business with good success.  It looks like they

might take internet credit card order now.  (Al Baldauski)

Try Grainger or Watlow.

I have used Watlow's flexible rubber electric heaters for bending sides (ribs) of acoustic guitars and other acoustic instruments. They can design whatever you want and put a temperature limit  switch on it, if desired, which may be a good idea.  (Dave Burley)

Take a look at what McMaster has to offer. I have always found them to be very responsive good guys to deal with.  (Mike McGuire)

...That's what I thought until I tried to order from them. Their web site ordering offers 'international shipping'. I duly spent a couple of hours putting together an online order and submitted numerous personal details, credit card number etc. A day or two later I received an email that informed me they would not process my order due to "ever increasing US export complications." If that is so I am not sure why they offer international shipping in the first place. I haven't had any 'export complications' from the other 6 or 7 US companies I regularly order from.

Pity.  (Steve Dugmore)

I have a friend who is building an oven and I can't find my invoice where I got my strip. Need sources for getting a heat strip to send him. (Tony Spezio)

W W Grainger is where I got mine. (Lou Barbaro)

I think the original source for the 650-watt mica strip heater came out of Wayne’s book, and may be listed in the appendix. I’m pretty sure that’s how I got mine, I remember it came from Michigan somewhere, although I can’t remember the name of the company after all these years.
Google search for mica strip elements turns up a bunch of sources.  (Tom Vagell)

When I built my oven some 14 years ago, I built my oven per the instructions of Wayne Cattanach's book. I purchased my strip from Grand Industries in Grand Rapids, Michigan. Not sure if they are in business today or not.  Can Wayne C. help you with this one? (Lew Boyko)

Yup, that’s the place! Not sure if they are still in business or not either. I bought my first one from them about 12 years ago, and second one about 4 years ago when I made a convection oven using 2 strips for faster start up.  (Tom Vagell)

I'm in the progress of making an oven as well. I will be using two 700w dishwasher elements that are straightened and controlled by an Auber PID.  Still working on the box. (Dana Fish)