Clear spray disk jig idea.

[The village idiot]

Umbearto gave me an idea, and I thought I would share. He is making a jig to use with spraying the clear protectant spray on his disk, so as to avoid getting the spray on the written side of the disk. I don't have any pictures or drawings, but just a description of this idea. Here goes nothing:

First take a sheet of soft plastic like vinyl or PVC or what have you. Now drill many small close together holes in this sheet (think vacuum forming of plastics) then glue small circular pieces of plastic, the size of the center of a disk, to the the perforated sheet in a spacing for several disks. Now take a sheet of disk thick vinyl or what have you and cut it the same size as the perforated sheet. Cut out a disk sized hole in the correct spots. Then glue a very thin sheet of vinyl on top of that. This top sheet needs cut outs that are just slightly smaller than a disk (like 1 or 2 mm smaller in diameter max) this will seal down onto the disks before spraying. Just make sure that the disks are spaced widely enough to allow a few holes between them to suck down the top sheet.

Now build a hollow box to fit beneath the perforated sheet, don't forget to put in supports for the perforated sheet in the middle of the box. If you forget the supports, then the sheets with the disk will be sucked into the box after the following steps.

Next bore a hole into the side of the box, and attach a small vacuum cleaner to the hole. Make sure that the vacuum gets enough air flow across the motor to keep from burning up! Do this by making a small hole in the vacuum cleaner hose, or bore several small holes in the box for the bypass air. A few inches of mercury of suction should be more than enough to pull the top sheet down onto the disks tightly enough to keep the spray from getting onto the bottom side of the disk.

Flip the switch on the vacuum, and start spraying. When done just turn the vacuum off, and lift the top sheet to retrieve the disks.

Alternately you could do with out the top sheet by just sucking the disks down tightly to the perforated sheet. Start with a center mount glued to a sheet of plastic. Then drill small holes for the disk to be sucked down with, just avoid any vacuum holes around the outside 1 to 1.5 mm of the disk. That should form a seal around the outside edge of the disk, but there might be more involded than that.

2 ideas for anyone that really wants to get into spraying their disks. Just don't let too much spray get sucked into the vacuum cleaner, it could bind the motor or cause a fire if the spray in flammable. Would be best to make the bypass air opening near the vacuum cleaner to thwart the intake of spray.

[Umbearto]

I think there may be gold here in these ideas. I have been thinking a vacuum could be used to filter spray fumes by taping an activated painter's mask cartridge to the hose and running that at the back of a large cardboard box I spray into... It never occured to me to use the suction to keep a masking film sucked down onto the discs..!

Thanks for the assistance VI... I'm going to do some experiments and see how it goes.

[gmatov]

Village,

Don't you think it might be a better idea to do the same as the mfgs do to dye the disks in the first place. They mount them on a mandrel, more complicated than that in mfg, but in essense, spin the disk while you spray.

Excess is thrown off by centrifugal force, no overspray on the back, write side, uniform application, as it is spinning at whatever speed you choose, no imbalance, gently wipe the edge as it spins, get rid of drops/droplets, that would remove the rough edge feel so many report with "grade D" media.

Loved your printer scheme, bitch that some prick sold your idea, first time I've seen you go to the hard way to do something.

Shopvac would work, but you have to worry a bit that the solvents in the spray might cause a "little bang" when they go through the vac. They're mostly volatile, read highly inflammable, you know..

Vacuum pump, even from a dead refrigerator compressor would be better, and draw a deeper vacuum, probably down to 100 millibar, maybe more.

Cheers,

George

[gmatov]

Oh, shit.

New idea.

Why don't you spray the damn things with an acceptable paint, spin as above, and print?

Possible you will get a paint that will take printer ink AND dry.

Cheers,

George

[Umbearto]

Very interesting thoughts George. You have a good point on the volatile nature of these solvents; a Xylene/Toluene/Acetone flash could be a little unfortunate....

I like the mandrel idea; I had been thinking about the use of an old/useless stereo turntable running at 78rpm inside my spray-booth/box, but there is no certainty the motor would provide spark-free operation.

Regarding overspray; this Krylon stuff is _very_ difficult to keep off the silver-side. My first jig design consisted of running a 15mm shaft with a 43mm flanged cap through the center hole of 2 CD's stacked. The cap to mask the stacking ring/hub and the second CD to mask the silver-side. This assembly was pressed into a 15mm hole in a cardboard box.

My thinking was; nothing lays flatter against the back of a disc than another disc. I could see no visible gap between the 2 discs, but the Krylon defeated this easily. We have to be talking microns of space here, and the spray penetrates as deep as 10mms past the outer edge.

My next idea consisted of using old jewel cases. I bought a tube of Bulldog Grip "Draft Stop" (A removable silicone based sealant). I ran a bead of this caulking around the outer-edge of the circular ring of the jewel case. I coated the silver-side of a coaster-CD with liquid detergent and pressed the CD into the caulking to create a nested mold.
I'm still waiting for the caulking to set-up, but if the mold protects the silverside, I will dremel off the center-ring holder and use my flanged cap rig to protect the frontside stacking-ring/center hub...

Once I can get a working jig design, I can focus on building a proper spray-booth/box with fume reduction. (This stuff reeks...!)

[Alan69]

I'm wondering..

What discs do you have that don't have a spacer ring on the bottom side around the center? These are spacers to keep the discs bottom surfaces from laying on any flat surface and scratching. Don't see how you were expecting two disc bottoms to seal..

Plastic bag taped around the shaft. Bag around motor and open to outside, fan on inside and in air piping. This will keep most of your fumes away from the motor, of course do this at your own risk and test it for yourself to make sure you get it correct. I take no responsibility if you try it of course, the mix could still be ignited by other means etc so it's still a bit hazardous..

Alan
.

[Umbearto]

I thought the spacer-ring on the bottom of "disc 01" would fit into the spacer-groove on the top of "disc 02". So it was bottom to top, not bottom to bottom. Either way, it didn't work.

(Disc 02 is just a coaster so it doesn't matter what happens to the silverside of it)

[gmatov]

I didn't mean for ou guys to get paranoid.

We're not talking a bomb, here. An AC motor only will make a spark at one point, and that is when the centrifugal switch opens in the starting circuit.

Spin it up, no more sparks. And, since you would not be spraying a great amount of material, no explosion.

I'd suggest a 1725 RPM motor, as 3600 might fling off all the material. I'd also suggest a hoop or arch of some material over the spinning disk, if you don't want to redo your ceiling, walls, furniture.

The plastic bags are a little overkill.

Cheers,

George

BTW, Village's printer, with Epson pigmented, moisture proof inks sound like the best way to go. As he seems to be amenable to reposting his guides, mebbe best you try that. No need for waterproofing.

[presto]

You guys have gotten my curious. I'm clueless here so be gentle. Why are you spraying something on your disks?

[Umbearto]

We're talking about Inkjet Printable Discs here Presto; once the image is printed onto the disk some people like to spray a clear coating/sealer overtop the image to protect it from fingerprint smudging and fading...

[gmatov]

Presto,

Unless you have an Epson printer, and use the waterproof, pigmented inks, just print a pic and drop a drop of water on your pic.

I think that will clear it up for you.

[presto]

Ahh, I HAVE ruined one or two disks that way. Thanks.

[civic]

Wow-- Some pretty fancy ideas! I've taken a more simple approach which, admittedly, is only good for one disc to be sprayed at a time. I use the following:

--Amaray brand DVD case (which has a continuous lip around the disc cavity and no thumbholes to interrupt it)
--a piece of thin foam material which I've cut into a circle slightly larger than a DVD, with a small circle cut out of the center as well. I used the thin black foam which is sold at Sears as Craftsman tool drawer liner material (not the mesh variety, this is the solid sheet stuff that comes in pre-cut drawer sizes).

I just pop the foam circle into the Amaray case and press the DVD down onto the spindle above it, sandwiching the foam between the back of the disc and the perimeter lip of the disc cavity. I spray Krylon 1306, and have not had a problem with overspray or seepage onto the backside of my DVDs. A nice thing about using the plastic DVD case and foam backing is that dried Krylon coating can be easily peeled away after each disc to create a like-new "jig" for your next spraying session.

The only problem I have is learning just how to best spray this Krylon 1306. It is REALLY picky about thickness of coat and has a bad tendency to orange-peel (dimples in the final finish where it didn't want to adhere evenly across the disc surface). Once it starts to orange-peel, there's nothing you can do...spraying more on it just compounds the effect and creates deeper dimples. I like as glossy a coat as possible, so it's frustrating when I can't get it perfect; I think I'm going to have to settle for lighter, more matte finishes. As for protection, I love the finish of the Krylon and I have no doubt that it's waterproof (haven't tried it, but I'm only concerned about protecting the inkjet-printed surface from finger smudges).

[Umbearto]

Good system you have there civic. A fellow called arcorob had a similar system I read about on this forum. Foam is definitely the answer here. I solved my overspray problem with a sheet of 1/4 inch packing foam I had laying around. I used spray adhesive to bond it to a cardboard box. Then used my 15mm shafts with flanged caps to press the discs into the foamed box. The box is big enough to do 8 at a time and the capped shafts protect the shiny foil ring around the hub on ritek discs leaving a very clean finish.

On the orange-peeling of Krylon #1306; you are experiencing the same results I have with the #1305. I can't spray that stuff in any number of coats to provide an even-gloss finish without dimpling. I have settled on the matte finish of 2 very light coats. It doesn't look bad at all, but sometimes you want something full-gloss... I had thought I would try 1306 next, but thanks to your post I think I may try the Krylon #1303 Crystal Clear with a glossy plastic finish.

[civic]

Hey, Umbearto-- Good luck with the Krylon #1303 and please post your opinion of it here after giving it a good test. I'm always interested to read about other peoples' methods and experiences on this stuff! Your comment about protecting the shiny foil area of the Riteks has me thinking... Up until now I've only used the full-printable BeAlls and have sprayed the entire surface, but I'm waiting on a shipment of Ritek G04s with the smaller printable area. I might want to protect that centermost area from overspray like you do. Thanks!

[themichael]

I wonder if the mat finish paints (white/clear) could be printed on?

I used to print on paper sprayed with mat paint but never plastic....

Anybody want to try on a coaster?

[The village idiot]

I've tried printing onto white THERMAL printable disks.... No luck with those, just a runny mess.