I’ve been using RR epoxy with the new X-55 additive to speed up my flip time for hotcoats, but so far I’ve noticed weird white streaks when I’ve been brushing out the hotcoat. It mixes into the epoxy pretty well and when I first pour it doesn’t look too bad, but once I try to brush it out it gets funky. I’ll try to take some pictures later. Also, when sanding it causes weird tiny pinholes? I’m not even sure if they are pinholes, but they are pretty noticable.
Any thoughts on what’s going on? Could it just be air bubbles? Thanks
I only use X-55 now for pinlines/resin panels, where the pigment will cover it up, and I can pull tape faster. I would get the same thing as well on hot/gloss coats, a cloudy/milky type of color, and sometimes it would go clear when curing, other times not. I live in West Texas, so I don’t think humidity was a problem, but I also don’t have a hygrometer to tell me how humid it is.
Hmm, well perhaps I should just give up on this one. I’d rather wait the 2-3 hours it takes to cure without it than continue with these white streaks.
I don’t think it’s a humidity problem, I’m working indoors, but it may be too cold. Unfortunately my dad only heats the house to 68 degrees F in the winter. I’m thinking of getting a space heater but I’ve only got a week left to work before I have to go back to school so it wouldn’t be worth it.
68 degrees should be fine, and since you are working indoors I would think the humidity is not the issue (unless it is damp in your house for some reason). I’ll definitely be tracking this thread to see what other more experienced RR users have to say.
I’ve not used RR X-55 but from your explaination, it sounds like it could also be due to the process rather than the additive. Contaminants such as substances left on the brush or in the pot that you are using to perform the hotcoat could also be causing this. Types of contaminants that could be suspects (off the top of my head) are:
Water
Acetone
Both could be in very small amounts on your brush or pot depending on how you clean them. Both cause the epoxy I use (West Systems) to get a cloudy / milky white appearance. I assume RR to have a similar reaction with or without X-55 additive, but I’m not the expert on RR.
I’d suggect you try:
If you used the same additive for lamination and didn’t get the problem, it may not be the additive.
Mix a small sample batch of RR plus X-55 (Maybe use a small clear container such as a clean plastic take-away container.) Let it cure and see what the effect is.
If the sample seems ok, try hotcoating using a new brush and/or a clean pot
If you get the same effect form the sample, contact RR.
I used to think it had something to do with excessive additive F. When I would mix the two caps of F/resin/hardener, stir it up a bit then dump in the X55, the X55 would turn light bluish and I’d get the streaks and some solids in the coat. Two caps was a bit much for what I was hot coating. Always used a new brush and container. Stopped using the X55 except for repairs.
I finished 2 boards in december. 1st one with x-55 I didnt get milkey streaks but the tiny pinholes were really a problem. Like the epoxy was kicking under the surface and making tiny air pinholes that were under the surface and could’nt rise. I was hoping the x-55 would help with lower temps in my shop.(not so good) 2nd board came out alot better with out the excelerator. I did crank up the heat some more. But I dont leave it on when I leave. Im not to sold on the x-55. I tried calling rr to talk to someone but didnt get anyone to call back. Tryed some in west epoxy and it definitly kicked faster. But the finish was not a factor then. I think film thickness is more of a issue with x-55 Mike
I’m glad to know that other people are having problems. Well, maybe not glad that it’s making such a mess, but reassured. I will try to take some pics soon but I just put pinlines on the board so it’s kind of hard to see the problem.
I will agree that it does look like bubbles are getting trapped underneath the surface, and this might be a cause of the decreased gel time. I think I’ll stop using it for now, it didn’t really save me that much time anyway.