gotta be an open diff.
ok, another update. I received the new resin. stuff looks nice, almost like a thick liquid glass before it's mixed. it's got way more body than the first stuff I used. the first stuff had the consistency of water almost. I had a lot of trouble even sealing my mold because it would leak out anywhere & everywhere. I used to have to really seal up the mold well by hotglueing all the seems just to keep it from all leaking out before it set up. well this new one is the exact opposite. now, instead of leaking out all over the place this one is just too thick to even fill the mold. it has the consistency of a very thick maple syrup, almost like molasses. I pour a bit in from the top of the mold, it just fills up the beginning of the fill tubes & just stops like it's already full, but it's not, it's just too thick to migrate all the way through the mold & completely fill it. I need to either redo the mold with larger fill & vent tubes or I need to try & get a syringe & develop a way to force it in, injection molding style which would be a challenge in itself. I tried to manipulate it & force it & was only able to get the reflectors filed about 1/2 way. with the first resin the cast would stay soft for a really long time, even a week later I could manipulate it & bend it, but the new stuff is very brittle & hard even just 48 hours later.. it actually shatters & brakes like glass, but that should be ok as once there installed there really not under any stress either, so even if they are like glass they should be ok.
also have another problem. the first watery resin mixed easily & whatever air bubbles developed would be minimal & easily just raise out to the surface & it would clear up after sitting for just a little bit, but this new stuff just is nothing like that... before it's mixed it looks clear as glass but after it's mixed it looks like one of those snow globes... I did research on best methods to mix without over aerating & stuff but this is way beyond that. because the resin is so thick the air bubbles just stay there.. some rise & pop but the bulk do not. when it cures it is not clear at all because of these tiny air bubbles. the solution to this is to buy or build a vacuum chamber. the way a material like this is worked with ideally is mix it, then insert in a vacuum chamber & apply 29" of vacuum to the chamber. the result of this is all the air bubbles are evacuated extremely quickly, it looks like it's boiling & even boiling over when this method is done, & it "boils" till all the air is out of the mix. it'll then be as clear as it was before mixing, & it'd be ready to then pour in the mold & get a crystal clear casting.
I have to get or build a vacuum chamber setup to work with this, only way. I thought maybe even if I couldn't really create a full vacuum chamber effect that maybe some vacuum might help a bit, so I made a makeshift setup with a 5hp shop vac. while that may move way more cfms than necessary it don't build up enough vacuum to really do all that much even in a dead sealed chamber... also found out the hard way that if there is any air leaks in this chamber setup then the vacuum will just suck up the liquid resin because of the airflow... was funny when I filled a 3oz mix, kicked on the vacuum for a second & saw the resin flying all over the chamber I tried to rig up, then turn it off & only have 1.5oz resin left
sealed it up better & then learned that many canisters will implode or collapse under enough vacuum too. even a thick glass jar can implode under the vacuum that is necessary for this type of thing from what I've heard, through conversations with a friend I've learned that a pressure cook pot or something can be made into a vacuum chamber, many real vacuum chamber setups are like 1/2" thick welded aluminum plate & 1" thick plexi windows... really needs to be stronger than you'd think... also need a good strong vacuum pump that can hit 29" & pull at least 3cfm's...
so far up until now I've been trying to work with materials that did not require degassing with a vacuum setup, but once we move up to more professional & higher end products then an accurate scale for measuring & a degassing setup becomes mandatory for good results... this is def turning into way more work & equipment than I ever thought it would be but this is the only way to do it at this point... now I'll work on putting togeather a proper vacuum chamber setup & continue
I can also test this new resin sample against the original... should be able to put it in an oven & little by little raise the temp & slowly bake it until I can get the original to discolor & start turning brownish beige... if the new one stays clear right along side then this would be a good confirmation that this material will at least do the job once I get past the latest hurdles with using it...
