Model, size, and # of heaters to use for heating a press

[mcfridge]

Hey everyone,

I've had a few posts on here about building a pneumatic press for making skis/snowboards, and ideas on how to heat it. I was talking to some people at Omega, and they said I could use either strip or cartridge heaters (the guy said that I could consider using cartidge heaters inserted into the mold (if it is metal) as these can provide good heat xfer when matched to a machined hole in your mold or die). Now, the mold isn't metal, it is mdf (so I'm guessing this rules out the cartridges). These are the approximate specs:

Weight of Mold: approx. 50-60lb, dimensions approximately 64" long by 18" wide
Mold Material: MDF fiberboard, topped with aluminum
Weight of Snowboard or ski's: approx. 5-10lb
Epoxy Manufacturer recomends heat curing at 190 F for 30min.
Voltage: household voltage 120V AC
heat up time prefer to be <30 mins

Can someone help me decide/calculate which model of strip heater I could use, the size, and how many I'd need? (

http://www.omega.com/toc_asp/subsectionSC.asp?book=Heaters&subsection=c01

)

The formula they gave me was this: kw = [(weight of material lb)(Cp)(temp. rise F)]/[(3412)(heat up time)]

Also, I've seen people use a heat blanket sandwiched between the sheet of aluminum & the MDF. Would I be able to put the heaters there, or would they have to be recessed into the mold? Thanks a lot for the help.

 

[GenB]

mcfridge,
When you have finished the molds, the winter will be out,
make yourself a mold to accept steam and get it over with.
and start making serious money. good investments will bring you good rewards
genblr