morepower
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Sorry... Been busy guys.. I am going to be building a new oven which will be more permanent and now I know my little (OK not so little) MDF oven was a proof of concept and I now need to look at going to higher temperatures I will post up a thread of the oven build and where I get my stuff from too..
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ECV3
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I bought a purpose built oven so never built the mdf oven. The case of the 2kw heater i have is metal not plastic and my plan was to put it inside the mdf box, hope that helps.
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thanasiss3
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Hello,at these ovens you put the 2kw heater in the oven?the plastic case of the heater can withstand at this high operation temperature? Or you remove the fan from the machine and attach it in the oven?
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ECV3
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Fasta (18/03/2015) I think your MDF may continually draw heat out since it is a solid type material panel.
I have 3kw oven that is a 2" foam core with thin sheet steel skins. It's 4m long x 1.1m wide x 1.1m high.
It will heat up to 100C in about 45 minutes with small light moulds inside.
For me in Australia 3kw has to run on 3 phase power. If it were 2kw then normal household single phase is ok.
Here most households don't have 3 phase whereas industrial workshops usually do.Hi Fasta I saw your oven on your video!, thats some oven!.
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ECV3
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morepower (17/03/2015)
No problem... I use a 3kw fan heater but it will work with 2kw if I wanted. There is a 50mm base of Kingspan which I put the MDF box on top of. I put the same Kingspan round the sides... well mostly I have to get some more to be honest but I am going to make a new oven soon as the shape needs a change. (MDF is cheap to use and try,if you find need to make changes), 10mm MDF is actually very good at keeping heat in. I have 2 degrees difference from top to bottom. One option I have been looking at is using a workbench for the frame as I had to get a 2.4meter long bench and the shelf seems perfect for the moulds I have. 900mm high, 900mm deep and 2.4m wide. I think it would would make a good oven with a bit of work. This is the inside of the current oven.. I only put my MTB in there to clear some space and give a mate an idea of the size... 3kw works perfectly with this sized oven. Hi Morepower, thanks for your info and pic!. I had the 2kw fan heater sat around at home so i can class that as no cost and my plan was to go with that and mdf and celotex\kingspan to keep it cheap so thats good news to me!. When i bought the controller unit ect the 5kw fan\heater unit came with it so if i ever want to build a permanent oven i've got them there. We must think alike i had a look at a workbench with the aim of converting it but with the price of galvanised sheet and kingspan ect (and not knowing i could use plywood ect) it wasnt cost effective so mdf it is!. Cheers.
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morepower
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Fasta (18/03/2015) I think your MDF may continually draw heat out since it is a solid type material panel.
I have 3kw oven that is a 2" foam core with thin sheet steel skins. It's 4m long x 1.1m wide x 1.1m high.
It will heat up to 100C in about 45 minutes with small light moulds inside.
For me in Australia 3kw has to run on 3 phase power. If it were 2kw then normal household single phase is ok.
Here most households don't have 3 phase whereas industrial workshops usually do.2Kw will work for me and it is a large area to warm up. But I dont ramp up that fast. The fastest I ramp up is 1 degree every 90 seconds. Not because that is as fast as it will go but because that is all I need it to go up by. MDF does warm up a little to about 36 degrees C (the door of my simple box) but the kingspan I have clad the outside with keeps most if the heat inside. The next oven will be more permanent as this was a proof of concept oven that works perfectly and is cheap. I can build a more solid one using an interlocking bench for a small workshop oven in my layup room. A bigger one using 90 degree steel frame, plywood, kingspan and some more ply for the inner skin it is trying to keep the metal which has a path to the colder outside to a minimum. A full MDF or ply inner skin which overlaps is the best option especially if you add rubber seals to the door frame so there is no real gaps.
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Fasta
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I think your MDF may continually draw heat out since it is a solid type material panel. I have 3kw oven that is a 2" foam core with thin sheet steel skins. It's 4m long x 1.1m wide x 1.1m high. It will heat up to 100C in about 45 minutes with small light moulds inside. For me in Australia 3kw has to run on 3 phase power. If it were 2kw then normal household single phase is ok. Here most households don't have 3 phase whereas industrial workshops usually do.
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morepower
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No problem... I use a 3kw fan heater but it will work with 2kw if I wanted. There is a 50mm base of Kingspan which I put the MDF box on top of. I put the same Kingspan round the sides... well mostly I have to get some more to be honest but I am going to make a new oven soon as the shape needs a change. (MDF is cheap to use and try,if you find need to make changes), 10mm MDF is actually very good at keeping heat in. I have 2 degrees difference from top to bottom. One option I have been looking at is using a workbench for the frame as I had to get a 2.4meter long bench and the shelf seems perfect for the moulds I have. 900mm high, 900mm deep and 2.4m wide. I think it would would make a good oven with a bit of work. This is the inside of the current oven.. I only put my MTB in there to clear some space and give a mate an idea of the size... 3kw works perfectly with this sized oven.
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ECV3
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The controller has 8 ramp/soak programs, 8 segments each. I have got TDS's for OOA pre-pregs that i may use but thats a bit down the line yet, for now my aim is to get a basic oven built and running, make some moulds and postcure them and get used to the controller and oven at the same time as i have no experience. If possible, cost wise i'd like to use the 2kw fan heater just to keep it basic and costs down, i have taken out all of the controlls just leaving the elements and fan so the ramp/soak will controll the elements, and the fan will be wired to run constant when the isolator switch is on. Thanks.
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ChrisR
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I haven't got any photos of it but the fan motor is outside with the spindle going through the side/end, through the insulation into an ally heater box, then using a centrifugal fan rather than you have in your photos. The element position is similar to yours on one and adjacent on the other due to space restraints. I run a tube (ally) into the centre space of the fan to suck air into from an area of the oven, it then gets blown over / out into another part of the oven. I also have 2 speeds on the fan but I only ever use the slower one. Ideally the controller you have should be able to control the temperature ramp rate and have one or two dwell periods, that way you can heat up to say 40deg to get the resin to flow and after say a B stage cure it can be taken up to 80 or whatever you want to use (check the resin datasheets for the ramp and dwell info). Depending on what I am making I tend to either ramp to 80deg at 0.5deg/min or I ramp to 40 @ 1deg/min dwell for an hour then ramp to 80 @ 1deg/min and hold for 8
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