I’m planning to do some tests with UV cure polyester in the vacuum bag (for fins).
I’m wondering whether simple UV blacklight ledstrips are enough to activate the UV powder catalyst?
If not, what type of UV light is needed, is UV-A good enough or is UV-B required? (which wavelengths)
As I’m planning to shine through the vacuum bag and breather cloth, I might need to build a high power UV curing box.
Any information is welcome.
I’m not sure how big the panels are you plan to make but the bag itself may be the problem. No uv going through.
I use uv resin in small batches in my day job and use reptile lights to cure it.
You can make a little box with insulation that has the foil on the 1 side. Works well to boost it s cure power.
Multiplelaters May be a tricky thing.
It might be best to mount some light under the layup glass and over it. Get light at it from both sides.
Yeah I realize the bag and especially the breather cloth might pose some problems. However, it should just cure tacky enough so I can get it out of the bag without delaminating, further curing can be done out of the bag.
Maybe I should just do a test with resin with both MEKP and UV powder and put it out in the sun to see if it cures faster than MEKP only. I’m not a huge fan of MEKP due to the smell.
I’m also wondering whether shining some very intense UV light on the bag might penetrate more than direct sunlight.
On the UVC 2000 user guide (http://suncure.com/UVC2000usersguide.html) I find an optimal range of 340nm-400nm UV light, however the closest LEDs I currently find are 400-410nm (https://be.farnell.com/vishay/vlmu3100-gs08/led-ultra-violet-405nm-plcc-2/dp/2395945?st=UV%20led), so I’m wondering how sensitive this range is. Building these LED panels will cost quite some of my time, so it would be great if anyone could save me some time on failures.
Edit: I found 365nm LEDs, but they are very expensive.
I doubt it will cure at all with the cloth in place.
If you run a heavy pigment in a single lam the top will cure but the resin underneath (on the foam) will stay wet.
I’ve even seen it not cure under a laminate.
Also, if your attempting to do a big stack(like 10+ layers at a time) that thing is gonna get HOT!!!
Thanks for that valuable link @stoneburner!
I got a reply from the surfsource guys about vacuum bagging, I’ll put it here for future reference:
SunCure should work through your breather cloth but as always, you’ll have to test for proper cure.
I’ll keep you guys updated when I find the time to do some tests.
If it were me I would catalyze the resin just enough for a very very slow kick then let UV cure it the rest of the way.