Printable View
Just curious if anyone uses a sandblaster for getting rid layer lines, or little bits here and there... If you went with really fine media I think it would work well and allow a few layers of paint to cover smooth.
thoughts?
looking at this one.
http://www.amazon.com/OEM-24815-Benc...TNY0TDF2E60F9Q
I have been considering this too. Might be a great little labour saver but am also not sure if it would work well on plastics.
I am really interested in this but since it is for hobby I don't want an industrial setup. However, I'm still looking for a "simple" machine :
- compressor
- spray gun
- "box" with see through lid
- recycling pump for sanding media at the bottom of of the "box"
Haven't been able to find an all in one kit. If you do find one, I'm game.
We recently had a pretty good thread on this topic. Searching might be able to find it.
I have access (well, it's my job) to a full professional setup (walk in 1 car garage size, space suit etc etc) and various other smaller setups, with grits ranging from 20 (tiny pebbles practically) to 250 (basically powder), I've used 36 and 54 grit on prints and have had decent results with them, but I'd want something in the 75 range to smooth them out pretty well, at something like 20-30 psi.
If I was set on painting a print, I'd smooth it with acetone first, then blast it to roughen up the surface. Otherwise, without the acetone, you'd be left with the layers and small gaps.
The other thread has a bunch of good links to home blasting setups.
As for saving money, I've been thinking about making my own for use at home, welding up a decent sized glove box using 1/8" Titanium plate (another thing I have practically unlimited access too, Steel or Aluminum, not so much), good sheet of lexan for a window (using thin clear plastic sheet for a disposable shield, don't want to ruin the lexan, and it'll go quicker than you think). I'd get a commercially available hopper and air supply, but I figure one could easily fashion a reclaimer/separator out of a funnel, some buckets, and a shop vac. The reclaimer would keep the grit to a standardish size, while getting rid of the dust.
well, i am primarily not printing with ABS, so acetone smoothing isnt my best option :)
with sandblasting, sure it will create pits etc, but it seems like a couple extra coats of paint may be able to cover up the roughness. maybe im dreaming.. seems to be no good way to smooth these prints.
you tried this stuff yet ? http://www.smooth-on.com/Epoxy-Coati...429/index.html
i havent tried that stuff . to me it looks fake.. I dont think it makes the part look very good. I think it rounds the corners so much etc... i cant put my finger on it, but i just dont like the look lol
I have a similar sand blaster cabinet. I tried it on PLA, also on DLP resins. Almost no effect. Maybe there is not enough pressure. But it did not work for me. Cannot recommend.Quote:
Originally Posted by dunginhawk
what PSI were you pushing through it hugues?
i have a bunch of different blasting setups and blast plastic parts all the time. the key to plastic or really anything is the media and pressure. you need to be using the right media. in my one cabinet i have crushed recycled glass. its very fine and cuts well. i turn the pressure down to about 40 psi and keep the gun at about 8" away. this keeps the media from digging into the printed part. its very much like spray painting a matte finish on your part. it does work nicely.......IF its the type of look your going for.
any pictures of some of your parts? im pretty sure ive seen some others in the past, just looks pitted and gritty right?
Thanks, probably this one ? http://3dprintboard.com/showthread.p...ght=blast+sandQuote:
Originally Posted by Marm
how do the sandblasted parts accept paint? obviously it will stick well, but is the grit fine enough that a few coats of spraypaint will smooth it out? or would you still see some of the roughness?
thanks
i dont have any pics unfortunately. last time it did it has to be well over a year ago. as for the finish and paint....again that all depends on media and how you blast it. it really doesnt cause pits unless you keep the gun too close or on the part in one spot and you start chewing the plastic away. its alot like spray painting. you have to keep things moving. there are tons of different medias in all different grit sizes. the crushed glass that normally is in my cabinet is very fine so a couple coats of automotive primer and paint would have no problem smoothing it out however if you were going to paint the parts then your not really gaining anything by the blasting. the blasting gives a very matte finish and hides the layer lines for the most part. it doesnt really remove the lines. they are still there. it sort of just blends them together a bit and makes them less noticeable. somewhere on the board there was a thread with some pictures. the thread might be gone though since i know we lost alot of threads and postings when the forum was down or being updated 4-6 mos ago.
I posted the link just above.
If you reduce your grit size, then it will get insanely smooth. If you get into the 100+ grits (140 feels like flour), it will leave a nice smooth smooth finish that paint will love. You can then use a rotary tool and some polishing grit on the paint itself (after it's well dried of course) to finish the piece.
I would actually be tempted if I had a home setup to try a few pounds of flour as medium to see how it works. This was just a brain storm, so something may be better, something that easily washes off, is easy to dry (probably not flour), and won't kill you if you accidentally inhale it.
So im giving a look to this one http://www.amazon.com/Gallon-Portabl...ds=sandblaster
its priced well enough... and has good reviews... I have a porter cable compressor already... so ill need a pistol to push the media.
Any recomendations on media type? or just any 100+ grit media? Any particular gun i should be aiming for too? this is all brand new to me :)
thanks
Quote:
Originally Posted by Marm
don't want to be overly cautious here but fine powder + air + confined area = risk of explosion
https://en.wikipedia.org/wiki/Dust_explosion
As a chemical engineer, I agree with Hugues.
Flour (or any fine carbohydrate particles) will make a highly explosive mixture when dispersed in air. It is not intuitive as we tend to see flour as a relatively inert material, but it is a real risc. The chemical (and food) industry has had a number of 'mishaps' in its history ...........
yes, if you want a fine media then buy a fine media or use the stuff in your cabinet until it breaks down and it fine. dont improvise. certain substances can get dangerous and extremely hazardous when blasting with them. sand is a prime example. never blast with sand. while we are surrounded by it every day, its super toxic to blast with. as the grains break when they hit the surface they will give off a gas that will kill you. i have a crushed glass here that is so fine its like baby powder. very nice for special uses like what we are talking about here.
lambda....yes thats the thread. not sure how i missed your post.
While I agree with the advice above about not "sandblasting" using actual sand, I don't think that it's really a gas that's given off when the particles break. What I've been told happens is that fine particles of unhydrated silica dioxide are released, which migrate deep into the lungs. There, they are attacked by macrophages (white blood cells) which can't handle it and die themselves, causing inflammation and scarring. In severe cases, death can occur within weeks or months. http://silicosis.com/types/index.php
Sand dust settling in your lungs : silicose. Not a nice one, be extra cautious and wear a mask.
I agree with the above, use proper sandblasting media and use a filtering system, you don't want that :
http://www.nytimes.com/2011/05/25/te...conn.html?_r=0
I get my blasting media from Key Abrasives, I recommend new and experienced people check out their website as it hosts a wealth of information about all the different types of media they sell and its uses.
I use a medium Iron Silicate for heavy work Cast Iron, rusty steel plate etc. and have 3 different grades of glass bead down to 75 microns for polishing aluminium. Its so silky smooth its like nothing I've ever had my hands on, its cool to the touch, softer than silk and feels thinner that water (not to be confused with crushed or recycled glass).
Once I've got my printer running a bit better and gained some experience I'll no doubt be throwing a few items in the cabinet to see what's what.
Yes, as mentioned, dust explosions are a concern. A legitimate one at that for fine improvised powder.
To be realistic though, anything that fine would be probably better done as a liquid grit and rotary sanding apparatus, like polishing grit.
It sounds to me like maybe you should investigate vibrating or rotary polishers/tumblers. These can be home made very easily especially if you have a 3D printer to hand. You place a finished part in the machine which vibrates and/or tumbles it about in a container full of abrasive chips.
Many different sizes, shapes and grits can be found easily and mostly cheaply.
Again this is coming from my engineering background, I'm totally new to 3D printing. I would use a tumbler on a lathe turned or laser cut part to give it a desired finish and smooth/debur edges - it could be very useful to the 3D print scene - then again, it could be completely useless!
http://www.metalclays.com/content/im...mbler_200.jpeg
Image from http://www.metalclays.com/p/332/dura...rotary-tumbler
Anybody use a Vixen blast cabinet, the wet types with Honite grit? Use these for removing fine but smooth surface machining marks from CNC components prior to anodising.
They are very controllable, but you have to wash them afterwards to remove the grit residue, as well as dry them off.