So we are switching from bagging in an envelope with a heat blanket to bagging against a flat surface with a hot box “cap” placed over the bagging setup. Heres the puzzler: what is a good surface material that is smooth, airtight, and wont start delamming at 180F under vacuum? Ideally it could be well insulated below the surface. I was thinking of building a torsion box workbench with insulation between the box ribs and a hardboard surface laminated on with resin (maybe a light glass weave to act as a glue line). Anything easier that wont break the bank?
Tempered glass. Call a few glass suppliers, see if they have something that is the wrong size.
I bought a 110x270 cm sheet of glass for just 100 euro.
how did you fasten down the glass sheet so it wouldnt flex? great idea though.
Not. It is layed on a custom made steel rig, which has self adhesive rubber stuck to the top, as not to damage the glass.
The backside of the glass has stripes on them (auto striping) every 10 cm, in a grid. That way we can see both top and bottom of an infusion.
I use both PP and metal. Steel/Aluminum plates for throwing in an oven, and our large tables are heavy duty steel ones (1/2-1") thick top. The PP one is nice bcause it releases without any mold release, but can become scratched VERY easily. Aluminum can be scratched as well if you don’t be careful, but is lighter than steel. Invar would be the best, BUUUUUT i doubt most people can find/afford that.
For heat…anything metal. PP might work for 180f. might need to experiment on it though. it might soften and warp.
How thick of glass do you use? Do you order it auto-striped?
riff42: PP is an interesting idea…I had thought of using treated-for-bonding UHMW laminated to a wood or hardboard backer for stability at temp. Might be able to do the same thing with PP.
The glass is some 5 or 6mm thick. Striping we had to do ourselves. Simple job, once we found out that we could stripe the topside, then turn the glass sheet around so the striping is on the bottom side… 
We installed an aluminium U profile around the perimeter to protect the glass. (glued with MS Polymer)
^ This, same set-up…our table is steel with tempered glass (10ft x 8ft), the benefit is you can get various glass sizes for specific jobs you maybe doing (ie. panels).
mattman: yeah, just check to see which one soften first, but I think they are near the same. We make mostly flat plates here for testing, so having a non-stick surface is great.
HOWEVER, now that I remember about it. When you pull a part off, carbon or glass…GROUND YOURSELF!!! Don’t know how many damn times I have shocked the bugger outta myself as the plate lifts off the plastic table. I have to grab one of the support table sides just to make sure I don’t shock myself.
Be careful about glass tops, tempered or not. Don’t thermal shock the part, or go too hot on just one side (ie: heater box placed on top one side, not the other)…might shatter it.
More fun to shock your buddy! Also isolate the table so edges don’t become grounds.
Remember. Stand on rubber mat. Pull vacuum bag as fast as possible with damp or sweaty hands. Wait till you have a clean shot at helpers exposed skin. Shock the person and say a clever insult. Run like hell!
It’s called “the e.t.” or “hot finger”.
Don’t lose your job over this though!!!
Un grounded table is dangerous. Only said to isolate it for shocking purposes.
Funny Dallas. Speaking of removing materials from the table. Has anyone seen the “blue light” when removing consumables? Sometimes it can be purple… Please tell me someone else sees this sometimes and I’m not going crazy seeing things. 
:nuts::blink:
wth are your consumables Roto? Neutron-reflective beryllium and plutonium? (read: Criticality accident)
If you aren’t going crazy, you might be dead shortly!
Stretchlon 200/ Enka blue flow media/ standard white poly peel ply/ PTM&W epoxy. I thought I read someone else had this experiance to on here…
YES!!! i did an infusion and i was demoulding late a night and had my snap on led tourch on the parts and as i was pulling the peel ply and the mesh off it was lighting up blue!!!
WTF … I turned my light of and carried on and yes as u rip it of i lights up really wired must be some sort of static???
THANK YOU!! I’m not going crazy after all, or dieing like Riff tried making me think. :sad2:
Rc posted on this as well. Years ago! probably don’t see it too much in temp and humidity controlled clean rooms.
Never had that problem, even when stressing the glass sheet a lot: 22 mm thick laminate with VE resin, got well over 120 C when curing, and was just half of the glass sheet.
Yep, Ours is pretty much the same as everyones. Steel frame on wheels, self adhesive foam tape and 12mm laminated glass. 2600 x 1200 cost $100 au as Herman said it was a piece cut the wrong size. We have a portable oven on wheels 2000 x 600 x 600 and just wheel this under the vac table with the doors open and build a quick box around it with polystyrene sheet 50mm thick and pin it together with welding rods. takes about 10min to set up. Not sure if it makes any difference but to earth we got a power cable and cut off the live and neutral pins and just left the earth pin and plug it into the socket and attach the other end to the vac table. Is the auto striping the small lines for demisting? if so how much heat can you get with that?
Hey everyone, just wondering what causes this? I’ve never been zapped??
Static charge. Like rubbing a balloon on something plastic and having it stick to a wall. Or sometimes tape being pulled off the roll. Happens a lot more in dry areas. Plastic tables with plastic bagging, and release, and polymer plates…when they are lifted off each other, somehow the static charge builds up. Once you get grounded…ZAP!