tu54 Posted October 15, 2003 Share Posted October 15, 2003 I've started this post several times and cancelled it. I'll see how far I go. The idea of running all the resin/hardner for this airplane thru a little paper cup in 6oz batches immediately struck me as needing a better solution. It's my nature. I first thought of having mixing parties on the days I work on larger components, similar to barn-raising parties. Or alternatively, hiring a small group of high-school kids. There are nice social aspects to this. I also spent time investigating Norm's approach, buying a few things, (like a large metal paint bucket which was to be painted red and sit in the corner for exotherm emergencies) and conducted tests. I played with paint propeller-based stirring tools. And I made stirring wires to use on my dremel against smaller batches. Not only did I have trouble making a balanced wire, tests with mayo & mustard showed that the walls of the clear cup I used was coated with unmixed mayo that I couldn't get mixed. I tried modifying my stirring wire but never was successful in getting a balanced wire that did the job. I searched the internet and found dispensing/mixing guns. Nice but too extreme for this job. Quote Link to comment Share on other sites More sharing options...
John Slade Posted October 15, 2003 Share Posted October 15, 2003 Why do you want to mix more at once? With the possible exception of finishing with micro I'd say that small batches are by far the best way. When epoxy is warm - say 110F - it wets out like water. When doing a big job like the wing you'll tend to mix 6 oz ot a time. Smaller jobs tend to be two or three squirts at most. Yes, perhaps you'll head back to the epoxy pump every few minutes, but you're wetout will be easy and quick, and you're layup will be good. When you mix too much (4 squirts, for example) it'll either cool down in the pot, or exotherm. My 2c Quote I can be reached on the "other" forum http://canardaviationforum.dmt.net Link to comment Share on other sites More sharing options...
Wayne Hicks Posted October 15, 2003 Share Posted October 15, 2003 There are always more than one way to skin ANY cat. My 2 cents but time saved by using a mixing tool might be negatively offest by the time needed to clean the mixing tools, then putting them together again for the next day's layups. With paper cups and stir sticks, clean-up is very easy. Just throw them away. Or wipe them out with a little acetone. I still use the very first cup and mixing stick from Chapter 4. :-) Mixing in smaller batches (1) lessens the chance for exotherm; and (2) gives the poured epoxy extra time to soak in while mixing the new batch. You'll find #2 to be the case if you're using the brown stuff (EZ-Poxy). ...Wayne Hicks Quote Wayne Hicks Cozy IV Plans #678 http://www.ez.org/pages/waynehicks Link to comment Share on other sites More sharing options...
tu54 Posted October 15, 2003 Author Share Posted October 15, 2003 You see, it's good to check newbies expectations against those much further down the road. Let me ask this, can you see much value to having a magical appliance which could safely and completely mix from 1 to 16 batches concurrently? I've read about how the wing or fuselage job took all day to get thru the job and assumed such a magical appliance could reduce that to a lazy 90 minutes. Reality check. I can very cleanly, safely, and completely mix from 1 to maybe 4 or 6 batches concurrently with manual techniques. Clean-up involves no chemicals. I can build a suprisingly simple appliance which will handle from 1 to 16, or even 20 batches concurrently, loading and unloading up to 3 or 4 batches at a time. I can take out some mixed batches, quickly load replacements for mixing, and then head off to apply my mixed batches. Quote Link to comment Share on other sites More sharing options...
John Slade Posted October 15, 2003 Share Posted October 15, 2003 >can you see much value to having a magical appliance which could >safely and completely mix from 1 to 16 batches concurrently? None whatsoever, except, perhaps during finishing. >could reduce that to a lazy 90 minutes. Sorry. The time is in the wetting out, stippling and strightening of fibers, not the pumping / mixing. >I can build a suprisingly simple appliance which will handle from 1 >to 16, or even 20 batches concurrently... might be handy... if you had 16 to 20 workers Quote I can be reached on the "other" forum http://canardaviationforum.dmt.net Link to comment Share on other sites More sharing options...
tu54 Posted October 16, 2003 Author Share Posted October 16, 2003 Well ok then, as said in Raising Arizona. I'll just scale it to do from 1-4 batches, still powered by a sewing machine motor. Quote Link to comment Share on other sites More sharing options...
dust Posted October 16, 2003 Share Posted October 16, 2003 you just need to start building, make sure you have a large clock to track your mix time, we use 1 min per batch and two size cups, small for 1 or 2 pumps and medium for 3 to 8 pumps, larger just aren't needed. enjoy the build Mike Quote maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build i can be reached at http://www.canardcommunity.com/ Link to comment Share on other sites More sharing options...
tu54 Posted October 16, 2003 Author Share Posted October 16, 2003 "you just need to start building, make sure you have a large clock to track your mix time, we use 1 min per batch and two size cups, small for 1 or 2 pumps and medium for 3 to 8 pumps, larger just aren't needed." What do YOU mean by 'batch' here? Quote Link to comment Share on other sites More sharing options...
tu54 Posted October 16, 2003 Author Share Posted October 16, 2003 I guess it's probably the same as my batch, nevermind. 1 minute? In my putzing I also tend to see that perhaps less than the Rutan 3 minutes is necessary. Thanks Quote Link to comment Share on other sites More sharing options...
John Slade Posted October 16, 2003 Share Posted October 16, 2003 >perhaps less than the Rutan 3 minutes is necessary... I'm sure that's true with MGS. They made the hardener a faint blue/green color so you can SEE when it's mixed. It only takes a few seconds of mixing for all the color to merge into the clear resin. Of course, scrape the sides while mixing to be sure all the hardener and resin are included in the mix. As for the batches - I don't think I ever pumped more than 4 or 5 pumps even when doing the wings (on my own). 8 pumps and you'd practically have to throw the cup at the part, or keep the hot box REAL close to the work area. My advice - forget the sewing machine and make some bulkheads. Quote I can be reached on the "other" forum http://canardaviationforum.dmt.net Link to comment Share on other sites More sharing options...
tu54 Posted October 16, 2003 Author Share Posted October 16, 2003 Thanks for the advice guys, bulkheads would be nice. Quote Link to comment Share on other sites More sharing options...
dust Posted October 16, 2003 Share Posted October 16, 2003 1 minute with 15 to 20 percent of the time on the sides and bottom. the deeper the cup and warmer the resin and hardener the easier to get a complete mix. As for color, it is usually uniform after 30 or seconds of mixing. i just use the cardinals(correct use of word?) 3 6 9 12 on the clock so a mix cound go to 1:14 but never to 59. All mixing done before adding micro or flox. in our slavedome we always have three ( the base masters i mean partners) and many times more and we ONLY use the ultraslow hardener, so eight pumps is no problem, it was when we used some of the faster hardener. If the epoxy starts to look snotty, put it to the side and mix fresh. So a batch only takes 30 seconds to pump and up to 1:15 to mix so ten batches only adds 20 mins to a LARGE layup. WEWH i could have mixed three batches writing this enjoy the build Mike Quote maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build i can be reached at http://www.canardcommunity.com/ Link to comment Share on other sites More sharing options...
Norm M Posted October 16, 2003 Share Posted October 16, 2003 So you understand all of my system that I used: Cups- Clear 9oz plastic cups, from Walmart. Tapered sides. Drill press- small bench mounted one with a floor mounted step-to-go switch Mixer- Red Devil paint mixer, propellor type with outer ring, plastic Procedure: Pump several shots of epoxy into the cup. Raise cup over mixer (like when they mix a milk shake at a real milk shake place) Step on switch to spin mixer Use other hand to close up hot box. ABout 10 seconds and you are ready to go. It works great for mixing micro also. Not near as much of the stuff floating around. I liked it because it was quick, but I also felt I got a better job of mixing out of it. I would take a popsicle stick and make about 4 swirls to make sure there wasn't anything clinging to the walls. The only time when I made really large batches was on things like the wings where the cloth was already in place. Then I made a few 20 oz batches. The great majority was three or four pumps. Cleanup- After 10 or so uses there would be icicles of epoxy hanging from the mixer. (I was going to say stalagmites, but couldn't spell it, and thought maybe stalgtites was the correct term.) A pass across the bandsaw cleaned those up, or maybe the table sander. When the holes filled in completely, throw it away and start with a new one one. If you want to make them last longer, spin them in whatever you use to clean brushes with at the end of the session. Worked for me! Regards- Norm Quote Link to comment Share on other sites More sharing options...
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