Hi everyone I have successfully poured and made molds with HS2 before- yesterday however I mixed and poured my biggest mold to date. (using 5lb ) I didn't use the whole container and I mixed by weight 10:1 my pour filled up about 90% of my object, but there was a small leak in my base so I let the HS2 start to cure. a few hours in, when the top was dry to touch, I mixed some more to "top it off" - my scale turned off when mixing the ratio and I think I ended up with a little too much catalyst in the mix.
it's been about 20 hours and the second pour has not cured. Is there any way to remedy this?
I was going to use the same logic, but no luck- the second pour is a real weird consistency... I tilted the piece so most of it could drop off and then I used a spatula of sorts to "scrape" the goop off the surface of what had cured below... I was worried though because there was no "clear" separation between what was cured and what wasn't- I guess the second pour may have afftected the first pour a little
I removed most of the second pour, but it was impossible to work with. left a hot mess that now I am trying to figure out how to "fix" on my mold.... because the core of the mold is done and cured, could I mix a new batch and pour it on top of the liquidy uncured part and hope that it somehow automagically bonds? if not, then what can I use to wipe off all the excess goop?
I am going to try to post some pictures to show what I'm working with this was after the first pour, it leaked from the sids and the level went down, the piece itself was still covered but the mold was thin and I wanted it thicker in those areas to avoid any possible tearing in the future... so I mixed and poured the second time...
this is the top where the goop came off
this is the cured "under" :
Last Edit: May 19, 2020 10:51:57 GMT -5 by kaotica
Your goal here is to get the mold as cleaned up as possible ( before you did the second pour)....once your satisfied with it as far as its appearance goes, go ahead and do you second pour.
Keep in mind that if you use anything Alcohol based , allow the Alcohol to completely dry/evaporate before doing a pour......allowing the Alcohol to evaporate will help insure that there will be a proper bond between the 1st and 2nd pour.
Alcohol breaks down the mold material so if you can don't use it to clean up unless you immediately wash the mold with soapy water at least once, maybe twice to be sure then let it dry. Lysol (wipes or spray) or 409 will break down the mold material - I use the Lysol wipes to clean up my work area and the 409 to clean up the mold material tubs so I can reuse them (after washing with soapy water a couple times) so I wouldn't use them unless you want to chunk the mold.
Your best bet for cleaning it up might be to just wipe off as much as you can with paper towels, try washing it with soapy water then wipe again with paper towels. Whatever is left will bond to the new mold material - I'm at least 80% sure it will. I had a mold disaster myself quite a while ago when I thought to try Flex 30 in the bottom of a mold box and poured Plat 25 over top of it and found out that Flex and Plat do NOT play well together. The top layer cured but halfway through to the bottom it was still a gooey mess and way beyond saving. I wiped off as much as I could, removed the Flex, carefully washed what I could off with soapy watch and a toothbrush, let it dry and poured a new batch of Plat with no problem. The little bit of Plat that was left bonded to the new and came out fine. I've also got a few molds where a previous mold left some behind (like under the edges of a casting) and a new one over top of it bonded to it and pulled out the old. I like to test the limits of my materials and this way is how we find out how they can be used in new ways and what they can handle.
thank you so much for the tips. I let the mold sit and I guess I removed most of the bad mix between the paper towel blotting and light scraping because it's now dry to the touch. it's still "sticky" but not tacky if that makes sense.
I am now trying to figure out how to remedy the original problem which was the "deep" part of the mold is way too thin and I want this mold to last several pours without tearing. I can't afford another $100 of HS2 just to thicken the back of the mold, is there a cheaper alternative to simply thicken the mold? I was contemplating regular silicone1 in a caulking gun which costs about $5 a tube and when cured I think would work, but I don't want to do anything that would jeopardize all my work to date. thanks in advance here is the essentially cured mold as of this morning:
I did a test on a scrap piece of Alumilite and the regular stuff stuck well, so I eded up making a wall around the mold and added a tube worth of the silicone to the back of the mold, specifically thickening the parts which were thinner. when it's dry, I'll use see how "level" the whole thing is and will decide wether to mix the little Alumilite I have left to level the whole piece out, or to use another tube of silicone to add portions here and there to level it out with the help of a level and polyethylene cutting board :-)