I have decided to share some of my experiences on making a heated press, mostly on a point of material supplies and usefull pages. In this short guide I will cover what I can both regarding pneumatic and vacuum press. I hope it will be valuable to you readers by saving you time and money, sweat and blood.
I found Happy Monkey Wiki very usefull in building a pneumatic press and building the heating control unit. Make sure you read this usefull page.
Further more for those who wish to press with only with one blanket you should carefully go thru this discussion,
Press
I made a press of H beams, 240mm. 2 in parallel and I ended up with a press 480mm wide, able to press kite/wake boards, ski and snowboards and also skate and longboards. If you are lucky like me, you might get it made for about 1000euros. It is a heavy duty forever lasting press.
If you go with a pneumatic press you need to address also the cat-track and fire hose issue.
I wanted to make it as simple as possible, knowing that more complex design would mean more chance of something going wrong. So I decided to eliminate the cat track part. For one because it adds to complexity, for other it acts as a heat sink, taking a lot of heat. For third it makes it harder to press complex shapes. I used a custom made blader made by ATL inc. This one enabled me to eliminate the cattrack and I had a very durable (made to last forever) press bladder.
If you decide to use a vacuum press, then you really would benefit from building a pressing table like the one Kristo from Fyra boards uses or the one OAC uses.
You can get the a sillicone blanket to use as a recyclable or permanent membrane on top of your setup. It is very durable and can last forever, and if you source it from China it can be cheap.
(this contact is not replying any more, please search Alibaba and contact 5-10 suppliers to get best chance of getting a hit) Contact Young from Young Fullchance Industrial Co.,Ltd, exporting@fullchance.com
Model: FC2211 – high tear strength silicone rubber sheet
Color: Gray transparent
Surface: Both sides smooth
Thickness of 1mm is more then enough.
Also regarding the size, dont be cheap, order more than you need just in case. I found that when working with vacuum, overdimensioning your press so you have at least 15cm extra, around your area you wish to press, beneficial. Otherwise it happens that the air get trapped and some air bubbles dont escape and its hard to fix.
Finally with regards to a vacuum pump, or a compressor for the pressure bladder, I have best experience with getting it in a local HW store. This way it is easy to return under waranty if anything goes wrong. I paid about 120 euro for each, so no need to get very expensive stuff.
Heat Blankets
As for the silicone heat blanket, I tried MEI, and the are really good. The quality is superb and I never had any issues with them despite pressing at 40psi or more at 80 degree or more. The price is not so low.
http://www.michaelsenterprises.com/custom-designed-silicone-rubber-heaters.html
However, MEI is a bit steep in price, so you might wish to consider a certified Chinese company that makes heat blankets to a number of big european companies, I have been using their blanket in vacuum press for more than 1 year now (2016) with no problem.
Company Name : Jiangyin Mengyou Electric Heating Appliances Co., Ltd.
website: www.jy83.com
wendy@jy83.com
Following spec is what works for most of us, internal temp. controller is not recommended due to problems suchas mealting or overheating due to melfunction or inaccurate temp.
230v,
2000-4500watt. The higher watts number, the faster it will ramp up and the max temperature will increase. However the current (Amperes) will increase and it might be your installation cant handle it. If you dont know much about electrics, talk to someone certified.
Current= Watts/Voltage supply.
180 degree C max
European 230V plug.
exit tab should be on the shorter side or the wider side.
NO built in temperature controller! It does not work for my application.
Heat Control Unit
For building the heat control unit, it is quite simple. You will need some wires, some plugs, a SSR relay, PID controller(s), probably a on off switch and some temperature sensors.
For my more expensive solution which probably costed me about 200-300 euro, I have done just like Happy Monkey and built a more advanced control unit that can be programed as you like to heat, hold and switch off, also called a ramp/soak. Auber PID is the type.
As for the temperature sensors, this is the best, and so thin and durable, that if you have extra money, it is worth it!
Omega, part #5SRTC-TT-K-36-36 for 5 type K thermocouples, and #RMJ-K-S for the connectors on the control box.
I also built a cheaper option which costed me probably not more then 50-100 euro. I used mostly Aliexpress, got a simple PID controller that only can ramp temperature quickly and hold it untill you turn it off. Also the temp sensors are not so durable and not so exact, but for a vacuum press it works. Search Aliexpress for a PID regulator incl. ssr relay and a temperature K type sensor and you will find it cheap.
Here is an example how it can be connected (be aware connector numbers might not be correct for your case!). Please use someone certified when playing with electricity. And make sure you ground all your metal components to be on the safe side to avoid any potential differences and current surges.