Post by squatsmcgee on Nov 29, 2018 9:30:04 GMT -5
Hey y'all Just bought my first alumilite clear casting resin. I have had mild success without a pressure pot or vacuum.
I took a round table top from the hardware store and routed a pattern in it. Then I used the casting resin to fill the pattern. It worked ok, all around the edges of the pattern were bubbled, i assume it is trapped air from the wood? Would a vacuum or pressure chamber help fix that?
I was decently happy with the result so I moved on... I stained the table top then decided to pour a thin clear layer over everything... somehow it got totally destroyed. Tiny white bubbles over the entire piece, basically ruining it completely. It was smooth as butter when I walked away from it, lightly hit with a torch as I have done in the past.
Am I missing something or is the pressure/Vacuum chamber just critical to this resin? Thanks in advance
The only way I've figured out how to embed an image is to post a thread then edit it to get the full stock of editing tools.
Now I don't use a pressure or vacuum system myself so I can't tell you if it would help or not. So let's go over your process and see if we can't figure out what happened.
1) Your working environment: are you working inside a room or outside? Most resins work best in around 70 degree dry environment and the clear is one of the pickiest resins about the surrounding air - especially with possible moisture levels.
2) Your pour: did you mix slowly in your mixing cup? Clear has a VERY long open time and you have to really be sure you take your time and almost move in slow motion to prevent as many bubbles as possible caused by stirring. Then you have to pour slowly and in a very thin stream - think hair thin sized stream. And it won't hurt to stop in the middle to rest your arm from holding it up for so long. Plus while you rest your arm, you can also lightly tap out some of the bubbles you might have missed. If you can't tap the item itself, you can tap/vibrate the surface under it.
3) Open time: you said you stained the top after pouring the clear the first time - how long did you wait between the staining and pouring the clear? Was the stain completely dry before you added the clear? Moisture from the stain could have reacted with the clear - moisture can be from any type of liquid, not just from water.
These are just three things we can start with to try to figure this out. Good news is you can *probably* sand the top coat that messed up off without losing the underlying design - just be careful and test a small area first to be sure. I hope this helps some.
Post by squatsmcgee on Dec 4, 2018 19:07:42 GMT -5
I really appreciate the help. I did not seal the wood with anything. I think I did not wait long enough for the stain to cure before pouring the epoxy. Additionally, I think the temperature drop (80 to 45) might have had something to do with my issues. I am familiar with mod podge but isn't that just a glue?
Is there a specific sealer that is typically used for this? I assumed minwax stain would seal the wood - certainly better than nothing at all... but again, perhaps I didn't wait long enough for the stain to dry. I poured on the same day I stained. Dry to the touch, but maybe not dry enough.
I see a lot of these projects done with wood that isn't sealed with anything. That raw wood look is sort of the appeal to this kind of thing... last year I made some rings with teak and a different epoxy and I had no problems, but teak is certainly different than "edge glued white wood" from Lowe's so I am not blaming the product for sure. Just trying to figure out where I went wrong. I would assume it was simply wet stain, but the bubbles formed over my initial pour as well so who knows.
Another issue I had was on a different project, the edges where the wood met the epoxy bubbled up over an inch high on either side. I was able to sand it down but the bubbles were so deep where the wood and epoxy met, it left a pocked finish.
The stain not being fully cured will add moisture which will normally cause a resin to bubble - I see this a lot with my "freshly made" molds (a post cure zap in the microwave helps the freshly made mold). Oh yes, a temperature drop like that would also do a (bad) number on resin. I know paper crafters swear by mod podge but I've never really cared for it. Especially when dealing with resins and molds. And yes it is more of a glue than a sealer.
Clear is a bit tricky, everything has to be perfect or it will fail so it could be more than one thing that caused the problem. I don't work with wood on a normal resin casting basis but I *have* used wood in construction so I do know that teak and white wood are definitely two different animals - going by that I'd say the white wood is a "softer" wood and absolutely need sealing. Especially when you throw that "glued edge" into the mix. But with what, I'm not entirely sure -
Can we have some of our woodworkers answer this please?
On your other project, when resin bubbles normally it's moisture as the culprit and sometimes it's just the moisture in the air that does it. To fix the pocked finish, you might have to completely remove the resin (there are ways to do this in addition to sanding) and maybe sand a little of the wood (depending on how thick the wood is) to smooth it back out. Your project might still be salvageable but it depends on how thick the wood is and what can be done for it.