I made a motorized finish mixer out of my old 20 rpm drying motor and it works really well. The finish dries hard on my wraps but the next day when I remove the left over finish from the cup, it is still sticky on occasions - I assume that it didn't get completely mixed. The article in the RodMaker magazine recommended any angle from 30 to 45 degrees and I built mine at 45.

I notice the 7/16" ball bearing rides down at the lower edge of the cup and it seems that it might mix better towards the 30 degree angle. I use the little FlexCoat cups and since they are at a taper, I'm really beyond the 45 angle and not rolling the ball exactly in the "middle" of the finish. I can easily take it apart and recut the angle, I was just wondering what angle most people use their mixer at? Thanks.

When I was using one of these "cement mixers" I did not use a bead at all opting instead to use a swizzle stick held stationary using a small goose-necked alligator clip on a weighted base to hold the stick stationary while the cup rotates. A simple positioning of the cup vs. the swizzle stick allows for pretty close scavenging of the sides of the cup for a more thorough mix. The cup was held completely upright.

Lou

Try a heavier, or a lighter ball. You don't want to ball to move up past 9 o'clock when the mixer is turning. Generally, a heavier ball is better. You want it to stay low, at about 6 to 7 o'clock in the mix cup for best results.

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I had the same problem, I must have mixed 25 batches and 90% of the time the cup would still be sticky in places. I tried different angles and size ball bearings and longer mixing times. I reread the article too many times to count and did a search here. I'm sure I never hit the right combo of angle and size bearings. I finally abandon the mixer and went back to mixing by hand. I think the cement mixer idea would work well but I didn't have a way to fasten the stick and by then I was fed up lol.

Please let me know if you ever figure it.
Thanks.

Thanks guys. Actually I dug out the article and after reading betweens the lines it sort of implies the angle references the container and not what the motor is housed in - duh! I recut the bottom angle and now the bottom ledge of the mixing cup leans exactly at 45 degrees. My ball bearing always rides a hair shy of 9 o'clock anyway so the only difference should be it will be centered in my mixture better. Thanks again.

i made one using a 3/4 oz lead head jig cut the elet and hook off. this is heavy enough to stay on the bottem,turn for 5 minutes scrape edges and its good to go. i have not had a bad batch yet. yes it stays sitcky on top , but after a couple days its sets up hard. i think it is because the left over finish is thicker in the cup then on the wraps. stan lothamer

I built mine just like Tim but I use 3 steel balls all 1/2" in size. With 6 CCs of mix, the balls are completely covered. With 5 minutes of mixing, I have no trouble at all.
Just my experience...Kevin

The first bearing I used was a round ball and I had the same problems you guys are having. I went over to the local machine shop and got a piece of round stainless steel stock 1/2 by 1/2 inch and put a slight champer in the edges. Now the metal bearing stays at the 6 o'clock and does not climb the sides of the mixing cup. I also get a complete mix.of epoxy and no wet spots in the cup.

Thats what I use in mine too a piece of 1/2" stainless rod stock never had a problem yet !
Maybe I shoudn't have said that yet part?

The whole Steel bearing problem with the automated epoxy mixer is the fact that the balls are round and the corner of the cup is near 90 degress; leaving a good deal of the mixture (and cup bottom and side ) untouched/unscraped. Most Mfgs directions stress scraping the cup, this does not happen in the autommated version because you want it automated and brainless when it is not fool proof in that respect only with regard to the entrainment of bubbles. The stick version that is mentioned seems to cover the most surface area of the cup if position so it lays up along the side of the cup thus scraping the flat side and the lower inside corner of the cup.

Whats left in the mixing cup for those who use Steel BB's of any size is the untouched/unscraped portion in the corner and bottom of the mixing cup. So you do need to mix big batches so your margine for error falls within acceptable norms and it sets up nearly everytime as it should. I'd guess if you tried smaller batches, you'd hear far more complaints and the best solution is a stand alone (almost "L" as it need not be 90 degres) "L" shaped scraping stick method, (as it can reach the corners, bottom and all the side of the mixing cup) OR what I'm waiting to hear about is a combination of both the scraping stationary "L" stick that help keep the BB in proper position.

I can also mix a batch in two miniutes without entraining bubbles and then save the clean up time for the BB's, and the Foiling, and the pre or post heating of the components/mixture respectivly. All while doing small 9 10ths gram total weight batches. If you mix a batch of thread epoxy and I mix one of the same Mfgs stuff (an identically proportioned batch). I will be appling it before you and have a greater pot life to boot, but a shorter pot life provides the time you need to clean up those BB's everytime

Good point Chris but in my FlexCoat mixing cups, there are 6 little ridges or bars (like in a real cement mixer) that I would think should mix the very corner of the cup whether the ball hits it or not. Since my cup was leaning forward too much, it was that area around the outside edges furthest from the ball that was still a bit sticky after a day. I like the idea of the 1/2" long piece of rod though.

I forgot to add my mixer uses the 2 oz. souffle cups which are smooth on the sides so the steel rod rolls the mixture together, it covers 1/2" up the side and 1/2" of the bottom just like the L shape mentioned in earlier post, as to where a ball bearing will only touch the side and bottom with 2 very small areas.