Plexi - first shot ...

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beamer

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Well, I spent a good 4 hours of intimate time with the Plexi finish today, giving it a try for the first time. I don't feel the symptoms I felt with CA as of yet, and it's been about 5 hours since my "exposure". So far, so good.

As for the finish. My initial impressions are that it has GREAT potetial. Only two coats and it was shining as clearly as maybe 4-5 coats of CA. I must say I was very impressed. It looks FABULOUS.

I have some bugs to work out, though. It's drying WAY WAY WAY too fast for me to cover an entire barrel evenly. I have plenty mixed up in the very thick form, so it'll just be a matter of finding a slightly slowe drying mixture.

My CA technique was with medium and I'd drop 5-6 drops on to the end of a folded up paper towel and wipe it on with the lathe off. I'd rotate the lathe by hand, spreading the glue on evenly over the entire tube. It dried slowly enough that I had plenty of time before the towel snagged at all.

This first batch was fairly thin, a little bit thicker than water, I'd guess. This stuff didn't immediately soak into one of those blue "shop" paper towels, but did soak in pretty fast. I tried a few techniques before deciding that I need to thicken the mix.

First I tried putting it on while the lathe was turning. I had a real tough time getting it on before it snagged the towel and left the surface all bumpy. I tried every speed on the lathe and I tried various amounts on the paper towel. I wasn't discouraged, because I had similar issues trying to apply CA "in motion".

So I tried applying it with the lathe off like i'm used to. This had better results. Still a little bumpy, because I had only 2 or 3 seconds before the paper towel would start to snag. Not even enough to get plexi on the entire surface, let alone evening it out.

After some practice runs, and a little cursing, I was able to get a good even first coat on. Starting with 2400 MM, I gave it a quick scuff and already I could see the shine coming through. I was able to quickly apply a second coat and sand that. Two coats came out looking VERY much like 3 or 4 coats of CA using my method above.

This is great news! My only problem is with the application. While I like that it dries so fast, I just can't get it on evenly before it starts dragging the paper towel. So my next move will be to try a thicker mixture. It makes good sense, since this first shot was a fair amount thinner than the medium CA that i'm used to. Hopefully the same theory for CA works in this plexi world. Thicker means slower, yes? I sure hope so :)

So all in all, not instant success. But it is off to a very encouraging start. I think a thicker mixture will solve my quick drying issue and so far I haven't felt any ill effects from this substance. I'll spend a little more time tomorrow and hopefully have some results to compare with my best CA efforts.

Happy new year! :)
 
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Thanks for the encouragement. Once I find the magic formula, I'll try to put together a recipe that'll give us a starting point for making a repeatable mixture. Something like x ounces of plexi to y cups of acetone.

Watching the stuff dissolve is very interesting ... i felt like I was in science class :P
 
What are ou using to disolve your in? I just picked up a paint can with a pourable spout & some plexi I got at lowes. How much plexi to acetone should I do for the first time?
 
I start by making a very thick liquid that way I can thin it down as necessary. I dont think that a formula for the thick solution is needed but for the thin solution I use 2oz plexi to 6oz acetone for the initial mix. Sometimes I will add a little more plexi or acetone as needed but always start the mix above. I usually flood the paper towel soaking it with the solution then applying. I am going to try playing around with spraying it to see how it comes out, one of the guys at my local Woodcraft has started using it as a spray for his flatwork.
 
I use a quart jar and an 8X10 piece of plexi (.20) and about 1/3 filled with acetone. I put the plexi in pieces on the bottom and poured the acetone on top and turned the jar over every day at first and then 2-3 times a day until is was all dissolved. Add to an 8 oz bottle and thin as necessary. Thanks to Terry for showing me this finish
 
Well it's the next day and i'm still not stuffed up. So far, so good!

I started two mixtures.

I put a little into a baby food jar, which got VERY thick after about 2 days ... no stirring really ... it just did it on it's own. The ratio is tough to guess as I hadn't thought to measure right off. The plexi was cut into ~1" squares and there's probably around a 1"x1"x7/8" cube in the jar. That seems like more than the acetone can dissolve. It appears to be saturated because 2 days after it became very very thick, it really hasn't changed much since and there's still a cube of plexi in the bottom ... about 3/4"x3/4"x1/2" maybe. They fused together real early on.

My second batch, started a few hours later on the same day, is in about the same state after 3 days. I used a 1pt paint can from the despot (the gray paint inside may come off ... i've seen some chipping already). This time I cut up 1"x2" pieces and laid them in there - not counting, but I'd guess it's about three times more than I had in the jar above. It seems to have reached saturation after about 3 days - with some stirring at least twice a day. Screwdrivers are great stir sticks, since this stuff doesn't seem to want to stick to metal very well.

I took another baby food jar and filled it about 2/3 the way with acetone. Then I just dipped my screwdriver into my thicker solution like a honey dipper. It took me a good 3-4 minutes of this dipping to reach a slightly thicker than water solution. I'm going to try a thicker arrangement today and see if I can't slow the drying time a bit. Once I nail down the viscosity that works for me, I plan to put together a better recipe that will help me come up with a repeatable formula.

here's hoping!
 
Jason, my plexi fused together also like that. I just left it a few more days and started inverting the jar. It eventually dissolved all of the plexi completely. But you don't have to wait for it to completely dissolve to use it as you've seen.
 
I wondered if it would eventually dissolve fully. After two days, the viscosity seemed about the same and the size of the blob didn't look much smaller so I just figured it was saturated. I'll keep an eye on it - as I use some of the top layer, I'll add more acetone and that should help dissolve any remaining globs.

A few minutes ago I began a little more precise experiment to hopefully get myself closer to a bit more predictability. There's 5g of plexi laying in the bottom of another babyfood jar with 30g of acetone. I'm pretty sure I'll need to add more acetone to get the viscosity I'm looking for, but should be a good start. This time, I broke the plexi into smaller pieces and this should speed up the dissolution due to greater surface area.

I'm beginning to consider stealing LOML's mortar and pestil to see if grinding a plexi powder would cut some of the time down, but that will have to wait - I have 3 batches going now and will need to start using up some of it - i'm running out of containers!

As an unrelated side note: Ever put styrofoam packing in acetone? FUN! :P
 
Jason, thanks for taking the time to detail this for the rest of us. I am also an interested onlooker.[:)]

BTW, what happened when you put your Styrofoam in the Acetone?[}:)]
 
Jason, I think it took close to two weeks for all of the plexi that I used to completely dissolve. But eventually there was no trace of undissolved plexi at all. I too think I'll break the plexi into smaller pieces and maybe add them over time to try to avoid the "lump".
 
Bob, It ... i dunno how to say it ... it ... umm... Have you ever seen those movies where some guy shoves his arm into a bucket of toxic waste and when he pulls out, his whole arm's gone? Same thing. I was able to cram a 1/2" thick, 1" wide, 24" long piece of styrofoam into a baby food jar thanks to acetone. It bubbles real nifty like and takes but a few seconds ... really nifty stuff. I left it overnight to see if it would dissolve and maybe provide another alternative finish, but it just sat there at the bottom so it's probably out.

Tommy, smaller pieces helps a TON. The 5g experiment is fully dissolved after less than 24 hours. The smaller pieces dissolved MUCH faster. I'm very tempted to make me some plexipowder, now. I'm sure I can buy it in pellet or granular form, but I'd much rather stick with the free source and mash it up myself if it's not too much trouble. :D
 
Originally posted by ozmandus
<br />I think I may have missed something... is this just plexi-glas being disolved in acetone?
an interesting concept..
Click to expand...

Chuck,

Yup! More accurately, it's acrylic that we're using. Polycarbonate won't work but looks a whole lot like acrylic. I have a place nearby that sells lots of surplus things and I can get my acrylic for about $3/lb - and that's a lot of plexi! :D
 
Cool, I haven't found anywhere to get it other than purchasing at Lowe's. But heck, I bought enough for $3.50 to last me a long time. Thought about trying to ask for scraps there, but they also cut polycarbonate and I can't tell the difference in the scraps and they're pretty quick just sweeping everything together.
 
I think that smashing it up will end up being more work than it is worth. Plus if you add to much at one time you will have the same lump you started with. This is the reason why I make a large container of the thick solution and transfer as necessary to my working container for the final thickness desired.
 
I worried about that, too, Terry.

This morning, the 5g experiment was a bit thinner than the first stuff, so I added another 5g of plexi to this mix. Note that this is now being called the 10g experiment [:D] I busted up this new 5g of plexi into very small pieces - nothing bigger than 1/4" square and 1/8" thick. I decided to just hang onto the jar this time and keep it moving. It's been about 2 hours now, and I have only teeny little pebbles in there. Obviously, stirring speeds up dissolution. I'm impressed by just how much faster it dissolved.

So grinding it up into a powder may be worthwhile if I can keep it moving long enough to dissolve. The clump only happens because the plexi's allowed to sit still for more than a few minutes. I kept this little jar moving most of the time and all the little pebbles are distinct little objects.

But the real upside is that they're almost done and it only took 2-3 hours instead of 24-36. If the pieces are smaller, it may only require a little stirring rather than days. It's kind of a side experiment for me to see if I can find ways to improve this finish as much as possible. It's more to satisfy my curiosity, but I also am glad to find progress where I can :)
 
I use Terry's method. I try to make it like a thick syrup. Then pour some into an 8 oz bottle and thin to the desired consistency. Saves me the trouble measuring [:D]
 
The latest experiment, I busted the pieces up into smallish bits and it made a huge difference in the dissolution speed. Instead of waiting several days, it took less than 24 hours.

Another help here is to keep the mixture moving. There are two reasons for this. One of the fundamental means of quickly dissolving anything is agitation (there's also heat and ... something else, i forget). The other reason to keep it moving is to PREVENT the plexi from fusing together into a single glob. One big glob is a huge reduction in surface area and you'll end up waiting longer.

The trouble with the last experiment insofar as dissolution speed, was that I basically couldn't set the mix down for more than 3-4 minutes. BUT, i managed to take the 24hr period and cut it down to less than 4 hours by keeping the whole mixture moving that whole time. WAY more work than I want to expend.

My next experiment in dissolution time will be to grind some plexi up into small pieces and see if I can find the absolute fastest means to dissolve all the plexi. I'm suspecting that I'll need to add the "dust" little by little intead of all in one big dump. But if a batch only takes 15-20 minutes to mix up, it'd be soooooo worth it to me. :)

I have my latest batch waiting for me to go out and test the viscosity/drying time. I got a little distracted this week and will be getting back into the swing of things sometime today or tomorrow.
 
hahah! excellent idea! :P

Well now that the wedding's over and the day of rest yesterday, I am all set to get back out there and try some more experiments with this. My bride and I just had to take a day of relaxation after the chaos of the inlaws and everything else before the wedding. Now that it's calmed down, I hope to have some useful info to post before the weekend's up :)
 
I start with a 1 quart mason jar about 1 inch deep with plexi pieces and add about 3 inches of acetone. That is my plexi-starter jar, it is a thick mixture (no need for waiting for all the plexi to dissolve). I pour off a few ounces into a clear plastic condiment bottle with attached lid ($.79 at Wal-Mart) and add a few ounces of new acetone - to between the consistencies of medium and thick CA. When the plexi-starter jar gets low I add a little more plexi and a little more acetone.

After sanding my blanks through 1000 grit, and the lathe at 1800 rpm I am ready to apply the finish. I fold a part of paper towel to about 1 inch across and put a latex glove on my right hand. 1 drop of finish on the paper towel run it on the underside across the first blank 1/2, 1 more drop for the second half. Less than 1/2 second of contact for each piece. Next pass in the opposite direction using the same method. Back and forth for about 20-25 coats - no need to wait for drying or to add contact time. Just drip-zip, drip-zip. 25 coats in less than 4 to 5 minutes and then wet sand through all the MM and a then few seconds with car polish.

From start to completion in about 10 - 12 minutes.
 
Well, after getting a lovely dissolved mixture about the consistency of medium CA, I had TROUBLE applying the stuff with the "one drop" method just described. I wasn't able to get good coverage with one swipe, and trying to supplement it with another drop created a disaster.

Next, I tried laying down a short line of plexi on the paper towel, and it wasn't much better. And sanding reveald some whitened pit marks and grain indentations that never blended into subsequent layers.

All in all, it was a MESS, and I didn't see much I could do to improve it. Any suggestion?

Galanw
 
Originally posted by Galanw
<br />Well, after getting a lovely dissolved mixture about the consistency of medium CA, I had TROUBLE applying the stuff with the "one drop" method just described. I wasn't able to get good coverage with one swipe, and trying to supplement it with another drop created a disaster.

Next, I tried laying down a short line of plexi on the paper towel, and it wasn't much better. And sanding reveald some whitened pit marks and grain indentations that never blended into subsequent layers.

All in all, it was a MESS, and I didn't see much I could do to improve it. Any suggestion?

Galanw
Click to expand...

Try Enduro. [;)]
 
That's exactly what I used after the disaster. It's great...but oh the wait.[:(]
 
Galanw try thinning it a little more then flood the paper towel with the solution. Wipe from one end of the blank to the other apply more solution to the towel and start at the opposite end and reapply to blank. I do this several times then wait a minute or so to cure then sand
 
I am sorry, fellas. I kinda fell off the train there. I had a hell of a time like Galan's having. Thicker was NOT better. Thin was decent, but I eventually ended up with a pretty cloudy finish overall. Not nearly as shiny as Terry's. I'm going to have to try again, too. I'm not defeated yet, but I got distracted again :P
 
I'll keep that in mind. I may need to give it some time before sanding, or something. I couldn't get it to stop clouding up on me. Both times I'd tried, though, it was well past my feeding time and I was lacking in patience :P
 
I've been keeping up with this thread and already have my plexi and acetone together in a jar. I'm going to try it tomorrow and I'll report back to you guys.
 
Did my plexi experiment and feel it wasn't bad for 1st try. It dried a little too fast but over all left a very shiny finish. Didn't have a problem with being cloudy but was a little tiny bit bumpy. Are you guys sanding after and then reapplying several times?
 
Becca I dont sand till the very end when I am done applying the finish. Make sure that you wet sand if not it will create to much heat. I have found that the heat unless it is totally cured will make the finish flake off. This is not a problem if the finish is totally cured though.
 
How does this method compare to the CA/BLO method? Why would one prefer one method over the other CA makes me cry/wheeze/choke but I wonder if acetone fumes might not do the same thing.

Also how does the plexi method compare to the dipping in lacquer method? I'm really liking this dipping in lacquer method. Time consuming but SOOOOO easy!
 
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Can't say that I know a thing about applying the mixture you're using.... BUT I can say that there are differences in acrylics. Picture framers use acrylic all the time and Cyro brand, Acrylite is the only sheet acrylic currently manufactured that is guaranteed to be crystal clear and to not yellow over time. All other brands, Plexiglass brand in particular, yellow very quickly with age.

My recommendation, once you get the process down to where you like it, is to only use Cyro Acrylite if you want a finish that stays crystal clear. When you can find it, Cyro Acrylite OP-3 has UV filtering additives that will minimize any UV effects on the object being coated. It doesn't matter whether you find it plastic film protected or paper protected. The product is the same and you are not worried about any scratches in sheet form.

Where to find it.... Many picture framers use it regularly and in most cases, pieces narrower than 5" are waste scraps that go into the dumpster. Call around and ask. The worst thing that can be said is that they currently don't have any.

How to make a powder.... use a sander with the coarsest grit you can find and just grind it to pieces.
 
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