Vibratory bowl finishing - ebonite and acrylics/resins

[henrya]

You may be in for multiple polishings. Something like first run with walnut and a slightly coarser compound than what you using now, then a run in the current stuff, and finishing off in corncob with really super fine compound. That’s three steps instead of one but the time might be the same or even less. Essentially like sanding with finer and finer grit sandpaper on wood.

 

[NewtonPens]

I am just screwing around calling you a city slicker. This website is strange and I am a newbie, some areas seem to be over moderated like no other I have seen, while long term members claim this place used to be everything goes. I am concerned about you claiming
lack of space, saying you can't put a box fan next to a tumbler. Does your wife or girlfriend insist on parking her vehicle in the garage? Is the closet full of all her shoes and different colored purses? I am new here but close to applying for social security, I need a lot of sit down breaks, so here I am.

Oh I know you're joking.

As for space - no my wife doesn't have any opinion on the space. As long as she can walk through it to get into the house, she doesn't care. I just don't have any more table top space where the tumblers are. But I don't think the temp is going to be a problem. It's been running more than 24 hours straight and seems to be doing fine. Hasn't gotten more than warm to the touch.

Right now I have a washer, a dryer, hot water tank, two small desk areas where I work at the computer and tune pens, a small area for my mill, a huge tool box, 2 cnc lathes (tormach 15L), a wood lathe for sanding, a big sink, and a Grizzly 4003g 12x36 lathe. My shop is an old single car garage that was expanded out about 6 feet, and it just barely fits everything I have. X)

view from my desk


you can see my tumbler setup on the right by the door. I need to build some small shelves above the black toolbox at the door and I'll be happier. I just don't want to drill into the brick.

 

[NewtonPens]

I have no experience polishing acrylics, a little experience polishing stones. I'm questioning your choice of polishing media, have you tried finer grits?
https://kingsleynorth.com/lapidary-equipment-supplies/abrasive-media.html

Right now I've only tried the green pyramids and whatever this grapenuts stuff is.

You may be in for multiple polishings. Something like first run with walnut and a slightly coarser compound than what you using now, then a run in the current stuff, and finishing off in corncob with really super fine compound. That’s three steps instead of one but the time might be the same or even less. Essentially like sanding with finer and finer grit sandpaper on wood.

Right now I'm at 2 steps, but if I eliminate the green pyramids and just go walnut then corncob, I should be alright? I already sand to 1500 by hand, and if I stick to just these two tumblers I'll be happy. Even if it takes 24 or more hours to run a load of parts.

 

[dalmatiangirl61]

Right now I've only tried the green pyramids and whatever this grapenuts stuff is.

I was referring to the use of car polish compound, it is an abrasive, maybe it is what should be used on acrylics? IDK

 

[NewtonPens]

Oh! I use this stuff mainly when I'm polishing the inside of clear parts. It takes a little while to sand it so it's ready for polish, but it does a really good job.
The polish I have in with the grapenuts is the finest one I usually use.
ooh - I just loaded it up with the 100 cut (coarser) polish, b/c that leaves a better finish.
I just ran a test piece on my lathe with polish on a paper towel. So hopefully that will speed things up. After almost 24 whole hours, the blue/gray part I showed above is getting there. I'm so happy this is working out for me.

 

[NewtonPens]

here are pics of 3 different materials after over 24 and 48 hours in the pot with the grapenuts looking walnut shell stuff.


This red is just your average run of the mill acrylic. I'm happy with how it turned out. It's probably the hardest material of the three and is generally the easiest to put a good finish on.


Green material is ebonite (hard/vulcanized rubber). Finish is nice and matte but not anywhere near where I would want it.


Blue Gray is alumilite resin - a 2 part epoxy material. The finish is about half way there. These parts sat in the tumbler for about 48 hours.




I bought some walnut from harbor freight and will try that out with the polishing compound thrown in after about 10 hours to see how that does.

 

[latheman78]

If that is only a one car garage + 6 feet you have a lot of stuff in there. I see you were unable to stand in line around those HF tool boxes without buying a couple. They do seem to be made decently for the price. Are you getting good action putting more in the bowl?
I did use car polish & walnut and got a good finish on some parts once but for the life of me I don't remember what they were. I have never run the type of plastics you are running.

Is that Tormach to the right have a slanted gang table on it? I would think those would be a real challenge to get lined up correctly for drilling.

 

[NewtonPens]

If that is only a one car garage + 6 feet you have a lot of stuff in there. I see you were unable to stand in line around those HF tool boxes without buying a couple. They do seem to be made decently for the price. Are you getting good action putting more in the bowl?
I did use car polish & walnut and got a good finish on some parts once but for the life of me I don't remember what they were. I have never run the type of plastics you are running.

Is that Tormach to the right have a slanted gang table on it? I would think those would be a real challenge to get lined up correctly for drilling.

Yeah both the lathes have gang setups, and it was a pain to get the drills set up. Center them, then shim them up. Rinse repeat until the drill doesn't wander up or down when drilling a fresh blank. No dial indicators or fancy setup tools. Would have been nice, but I can't see spending a ton of money on a tool I'll only use a couple times then never again.

I do really like the HF tool boxes, too. They hold my blanks and mandrels and lots of tools and stuff. Before I got those the shop was a real mess. Now it's just crowded.

I think the walnut is doing a better job than the grapenuts. The box labeled walnut was for sure not. I had a box labeled dry shine and turns out they're the same as the walnut from HF. Lots of polish added slowly over the day and I'm starting to get some good results. Hopefully by the morning or tomorrow afternoon I'll have something I can share here.

 

[NewtonPens]

Here we go.
Walnut with meguiar's 100 cut car polish slowly added-

24 hours is fine with hard acrylics.
It's mostly good with alumilite, some parts are shiny, some are dull. Maybe had too many parts in the bowl?


Ebonite is just slightly less matte than when it came out of the pyramids.





I could be done with it and just do a final pass with my last buffing wheel, but I don't want to.
What kind of finish might I get with gray rocks?





Thanks

 

[kustomizer]

We polish here with 3mm ceramic balls and het good results though it has been a long time since I did any acrylic parts

 

[latheman78]

Yeah both the lathes have gang setups, and it was a pain to get the drills set up. Center them, then shim them up. Rinse repeat until the drill doesn't wander up or down when drilling a fresh blank. No dial indicators or fancy setup tools. Would have been nice, but I can't see spending a ton of money on a tool I'll only use a couple times then never again.

Someday you will need those "fancy" set up tools. I am guessing you have a young set of eyes. Remembering some of the things I used to do would sound like an old timer telling BS stories, if I shared them.

 

[latheman78]

Here we go.
Walnut with meguiar's 100 cut car polish slowly added-

24 hours is fine with hard acrylics.
It's mostly good with alumilite, some parts are shiny, some are dull. Maybe had too many parts in the bowl?
View attachment 371616View attachment 371617

Ebonite is just slightly less matte than when it came out of the pyramids.

View attachment 371618

View attachment 371619

I could be done with it and just do a final pass with my last buffing wheel, but I don't want to.
What kind of finish might I get with gray rocks?


View attachment 371620


Thanks

I used those with some water soluble valve grinding compound as a last step to get a nice finish on some 1018 parts. That could be another polishing option as it gets finer as it breaks down. I will post the name of that stuff later. I hope you are keeping a diary on these experiments or have a great memory.

 

[NewtonPens]

The diary is this post, and I'm labelling stuff in gallon baggies and boxes. Right this minute, with the parts dried off, I'm running dry walnut with some ground up white buffing compound. The stuff that comes in a brick. I used a rasp and basically grated the compound into the walnut. We'll see what that does. My next step is exploring hard wood cubes and pegs.

 

[latheman78]

Have you ever tried spinning the round ones in a lathe and using a fine steel wool? What they sell at HF is usable. That did work, but I don't remember on what, ha,ha. It has been too long.

 

[kustomizer]

Steel wool, sandpaper etc leave a much finer finish if you rub it on a candle first, damp fiberglass insulation is finer yet

 

[dalmatiangirl61]

With rocks, you use progressively finer abrasive media with known values, the ceramic beads/diamonds etc are just filler to keep the rocks from grinding against each other. The ceramic media will pickup the abrasive media, so those are only used with that particular size of abrasive, when you change to a finer abrasive, you change the ceramic media too.

 

[latheman78]

Steel wool, sandpaper etc leave a much finer finish if you rub it on a candle first, damp fiberglass insulation is finer yet

When I tore out a couple walls due to leaky pipes I threw out the moldy damp insulation, no idea it had a use in the shop. I wonder if all the mouse droppings I found could be repurposed?

 

[kustomizer]

When I tore out a couple walls due to leaky pipes I threw out the moldy damp insulation, no idea it had a use in the shop. I wonder if all the mouse droppings I found could be repurposed?

They look like those things I see sprinkled on cupcakes, ain't tried them for that reason.

 

[NewtonPens]

I've played with steel wool before and it wasn't worth messing with. A jeweler friend of mine got me to try it a few years ago. It's not as nice as just using good quality sand papers.

 

[latheman78]

I've played with steel wool before and it wasn't worth messing with. A jeweler friend of mine got me to try it a few years ago. It's not as nice as just using good quality sand papers.

I did a bunch of oddball plastics and the sorts dabbling in DOD work decades ago. So who knows what it worked, on, it might have been some type of nylon??? I am just throwing stuff out there.