Model Engine Maker

Supporting => Tooling & Machines => Topic started by: Jo on March 09, 2019, 04:49:02 PM

Title: Cheapo sandblaster upgrade
Post by: Jo on March 09, 2019, 04:49:02 PM
Along with my new compressor came a cheapo sandblaster  :mischief:

I have been told that the main problem with these is that after about 10 seconds you are trying to blast through a sand storm so cannot see anything   :Doh: This could be solved by putting a vacuum cleaner the other side of the filter but that seemed like hassle so I opted to add an old test equipment fan that I had laying around. This provides the necessary howling gale out of the side of the cabinet  :ThumbsUp:

The next job is decide how to run the electric string  :thinking:

Jo
Title: Re: Cheapo sandblaster upgrade
Post by: b.lindsey on March 09, 2019, 06:51:22 PM
Jo, that may help but the other issue I have had with similar units in the past if the filter clogging up which can render that fan or even a vacuum much less effective. Hope you have better luck.

Bill
Title: Re: Cheapo sandblaster upgrade
Post by: gerritv on March 09, 2019, 09:23:35 PM
I have a similar  unit and will be putting a cyclone dust collector in between the cabinet and the vacuum. Media drops into a bucket, so I can reuse, and the vacuum cleaner filter stays relatively clean. Already have one set up for my table saw in the garage.

Gerrit
Title: Re: Cheapo sandblaster upgrade
Post by: b.lindsey on March 09, 2019, 09:28:11 PM
Gerrit, in doing that do you remove the filter inside the cabinet?

Bill
Title: Re: Cheapo sandblaster upgrade
Post by: crueby on March 09, 2019, 09:32:38 PM
I have a similar  unit and will be putting a cyclone dust collector in between the cabinet and the vacuum. Media drops into a bucket, so I can reuse, and the vacuum cleaner filter stays relatively clean. Already have one set up for my table saw in the garage.

Gerrit
Gerrit, in doing that do you remove the filter inside the cabinet?

Bill
I have the same thing (Dust Deputy units) on my wood shop and metal shop vacs, the cyclone captures an amazing range of size material, from fine dust to big chops. A little bit of the fine material will occasionally make it into the vac, also once in a while it will suck up a bit of paper towel that will go through into the vac, so I would leave the filter (a clean one) in place. The only time I've gotten a lot into the vac is when I didnt notice the bucket was full, and everything after that went to the vac.
Title: Re: Cheapo sandblaster upgrade
Post by: b.lindsey on March 09, 2019, 09:37:14 PM
The issue I had with clogged filter inside the cabinet was that when blasting, it would tend to inflate the cabinet a bit and dust/ media would get out through the seals.

Bill
Title: Re: Cheapo sandblaster upgrade
Post by: crueby on March 09, 2019, 09:39:18 PM
Sorry bill, on my reply I was thinking of the filter in the shop vac, forgot about the one in the sandblasting cabinet!    :Doh:
Title: Re: Cheapo sandblaster upgrade
Post by: Dave Otto on March 09, 2019, 10:15:56 PM
If you put a vacuum on the cabinet it is also a good idea to have a place for the air to enter, so you have a constant flow through the cabinet. This is the way the industrial units operate.
My little home built unit has vents above the lights where the air can enter. There is no filter inside the cabinet.

I picked up the nicely made stainless steel cyclone separator form a friend who was scrapping out some hi-tech manufacturing equipment.
I need to make and install a baffle plate over the exhaust intake because the way it is now some of the media gets pulled out of the cabinet.
Not a big deal, I just pour it back into the cabinet form the cyclone.

Dave
Title: Re: Cheapo sandblaster upgrade
Post by: gerritv on March 09, 2019, 10:18:24 PM
Gerrit, in doing that do you remove the filter inside the cabinet?

Bill
My cabinet didn't come with a filter. The filter in the vacuum cleaner stays clean for a long time. As noted, the majority ends up in the cyclone bucket.
LeeValley now has a nifty type that replaces the lid on a 5 gallon paint bucket. Less money as well. I think one of those will go on my tool grinder soon with a BucketHead (https://www.homedepot.ca/product/bucket-head-wet-dry-vacuum-powerhead-lid-for-19-litre-5-gal-multi-use-buckets) to provide the suction.
Title: Re: Cheapo sandblaster upgrade
Post by: Jo on March 10, 2019, 07:56:46 AM
Thanks Guys this is a new toy for me so all suggestions welcome. I did consider making a cyclone but they increase the size of the unit. This is important as I will be using the blaster in the garden not in the workshop  :hellno: so there is a need for the entire unit to be compact as well as portable. The back of the cabinet already has a vent for the air inlet  :ThumbsUp:


Electrics wise the LED lamp is a 12v unit same as the fan so I may try just hooking it up on a old 12V car battery to avoid running mains cables. I will have to run the air line out to it but that is sorted as I have brought myself :naughty: up a auto retract air hose for the new compressor   


My current plan is the unit will be used sat on my workmate with the blasting media housed in a bucket under the cabinet with the gun suction hose poked through the hole in the bottom of the cabinet into it.  :noidea:

Jo

Title: Re: Cheapo sandblaster upgrade
Post by: Bluechip on March 10, 2019, 09:32:36 AM
Hi Jo

Found a piccy.

This is the one I had all those years ago ...  :old:  Don't remember mine having the 'go-faster' stripes on it. Just blue .  :thinking:

http://www.simmomach.co.uk/used_machine_tools/miscellaneous.php?pid=1149



Dave



Title: Re: Cheapo sandblaster upgrade
Post by: Jo on March 10, 2019, 10:14:04 AM
 :thinking: I don't think even I could lift that in and out of the garage if I wanted to use it Dave.

Electrics done on the cabinet so time to hook up the compressor lines in the main garage.. all except the last bit as I am still waiting for the tail  :-\

Jo
Title: Re: Cheapo sandblaster upgrade
Post by: Bluechip on March 10, 2019, 10:49:11 AM

 :thinking: I don't think even I could lift that in and out of the garage if I wanted to use it Dave.

Jo

Didn't have to.  :ThumbsUp:  No dust came out of it ... ( providing it was used in accordance etc. etc.    ::)  ).

P.S. Do you have the neoprene gauntlets to go with the set-up or were you contemplating going down to the bone on your fingers ???    :thinking:

Dave  ........  Sun's shining now    :)  Snow's just about gone. Might just venture outside.  :noidea:
Title: Re: Cheapo sandblaster upgrade
Post by: Jo on March 10, 2019, 11:06:38 AM
These cabinets come with the rubber gloves. You couldn't make and fit out a blasting cabinet for the price of these units.

Jo
Title: Re: Cheapo sandblaster upgrade
Post by: Vixen on March 10, 2019, 11:26:06 AM
These cabinets come with the rubber gloves. You couldn't make and fit out a blasting cabinet for the price of these units.

Jo

I bought my blasting cabinet from a motorcycle importer. He usually imports a shipping container full of motorcycles at a time. They only occupy the floor level so he fills the space above with big boxes of light stuff, usually sand blast cabinets and engine parts washing  bowls.

Mike
Title: Re: Cheapo sandblaster upgrade
Post by: Graham Meek on March 10, 2019, 11:55:05 AM
Here's one I made sometime back, cost less than 15 / $20. Most of the items came from the workshop, and the DIY bits held in my stores. For my occasional usage, and the small work I do it suits my needs. A big plus is it does not take up any bench space and is stored away beneath the bench when hot in use. Being portable it can be used outside so dust in the workshop does not become a problem.

Regards
Gray,
Title: Re: Cheapo sandblaster upgrade
Post by: ChuckKey on March 10, 2019, 04:55:19 PM
My current plan is the unit will be used sat on my workmate with the blasting media housed in a bucket under the cabinet with the gun suction hose poked through the hole in the bottom of the cabinet into it.

I have one that looks almost identical. The blasting media sits in the trough at the bottom of the cabinet.

I think I don't have enough of the stuff, as I am constantly shifting media, or the end of the suction tube, to try and get them to be in the same place.
Title: Re: Cheapo sandblaster upgrade
Post by: Bluechip on March 10, 2019, 05:15:12 PM
I seem to remember with mine that the pick-up tube should not be buried deeply in the media ...  :headscratch:  needs to pick up air to entrain the grit / whatever.

Another gotcha which usually occurred after I had not used it for a week or so was it's reluctance to deal with damp media.  ( I think that was just glass bead though  :thinking:  :old:  ... it was some 45 years ago ...  :facepalm2:  )

So, a moisture separator is essential ... and empty the thing regularly ..

Dave


Title: Re: Cheapo sandblaster upgrade
Post by: Jo on March 10, 2019, 07:43:11 PM
Thanks Dave,

Yes I need to enable an air flow to the bottom of the siphon tube or it will restrict the amount of sand it can pick up. The sand is going in an air tight bin which should help keep it dry and I am plumbing in a decent moisture trap on the new compressor hose..... but am still waiting for the tail to do the final connection  :disappointed:

Jo
Title: Re: Cheapo sandblaster upgrade
Post by: Jasonb on March 10, 2019, 08:05:22 PM
but am still waiting for the tail to do the final connection  :disappointed:

Cut one of that elephant :LittleDevil:
Title: Re: Cheapo sandblaster upgrade
Post by: Ramon on March 10, 2019, 11:07:32 PM
Hello Jo

I don't know if this will be of use but I've had an identical cabinet for quite some time now - the inside light packed up quite quickly (still not replaced) and I've never coupled up a vacuum to it but I've never had any issues with using it :) - for what I do

One thing I would point out though was that before I got mine I used to use a friends purpose built one - he used to have a small piece of carpet laid inside to lay the components on. I followed suit with a small piece of doormat laid on top of the inner open mesh layer. Shortly after this I began to experience a 'diminishing of effect' of the bead and it took a while to realise that the carpet was also being blasted and the fibres were contaminating the bead, building up unseen and preventing the suction pick up in the bottom of the cabinet.

Once realised I easily resolved this - so I thought - by using a kitchen sieve to filter out the fibres from the bead. This did not solve the problem however and it was only after I stripped the gun head completely - along with it's pick up tube - that I found all the internals completely clogged with fibres ::) Despite a high-ish pressure (140 psi) and volume output from the compressor that was still sufficient to prevent the bead from flowing adequately for bead blasting.

Once cleared I also reversed the mat to present the rubberised underneath to the bead and though much slower in resisting the  effect above as I did these latest engines I have found that the same thing was beginning to occur but this time with rubber fragments.

Just something that you might want to note but overall I do not use anything to improve the basic use - I don't find any problems with the small items I require it for, indeed for the relatively small outlay it has been a brilliant addition to the workshop

Regards - Tug

Title: Re: Cheapo sandblaster upgrade
Post by: Jo on March 11, 2019, 08:36:09 AM
Thanks Tug, we probably will be using it for the same sort of thing  ;)

I was thinking about what I could put bits on to blast them. Some of my castings are rather small and I wouldn't want to loose them  :o

Edit: I might have found a suitable casting container for holding bits while blasting  :noidea: I also have some much finer stainless mesh but I suspect the grains will catch in there.

Jo
Title: Re: Cheapo sandblaster upgrade
Post by: Ramon on March 11, 2019, 09:27:03 AM
Hi Jo - if it's glass bead you are using then that sieve will be fine - it looks to be the same mesh as I used to filter out all the fibres.

Not so sure if you intend using grit though - I've only ever used the glass bead in mine

Regards - Tug
Title: Re: Cheapo sandblaster upgrade
Post by: petertha on March 11, 2019, 06:40:19 PM
Graham, what a great idea re purposing the plastic container for the chamber! Dumb question - what am I looking at here on the business end of the sand blaster. The trigger nozzle looks like my shop air blaster. Is the metal thingy on the inside a siphon draw for the abrasive medium? Is this a commercial thing or something you adapted?
Title: Re: Cheapo sandblaster upgrade
Post by: Graham Meek on March 12, 2019, 11:50:13 AM
Hi Peter,

The steel piece on the end of a standard air-duster/blaster is indeed the siphon which is homemade. The plastic feed tube is pushed into the steel piece such that the air-duster/blaster nozzle is blowing over the end of the tube. Any wear that takes place is easily remedied by cutting a slice off the tube. My tube was 6 mm diameter and I found the tapered end of my hand reamer gave a very good press fit in the steel piece. The eccentric portion of the siphon is to allow a longer "fit" for the 6 mm tube.

I built this unit to match my existing compressor, most commercial units need a higher flow rate. This set-up does all I ask of it.

I hope this helps,
Regards
Gray,

Title: Re: Cheapo sandblaster upgrade
Post by: Vixen on March 12, 2019, 12:11:47 PM
Hello Gray

Thats a tidy and convenient sized blast cabinet for doing out kind of small work. Looks good, well done. :ThumbsUp: :ThumbsUp:

Do you have a sketch of the siphon bit? I cannot quite visualise your description.

What do you consider to be the better blast media and where do you recommend to buy it from?

Thanks in advance

Mike
Title: Re: Cheapo sandblaster upgrade
Post by: Bluechip on March 12, 2019, 12:34:36 PM
Hello Gray

Thats a tidy and convenient sized blast cabinet for doing out kind of small work. Looks good, well done. :ThumbsUp: :ThumbsUp:

Do you have a sketch of the siphon bit? I cannot quite visualise your description.

What do you consider to be the better blast media and where do you recommend to buy it from?

Thanks in advance

Mike



www.bing.com/images/search?view=detailV2&id=9487627C206FA7DBE03BD44AD5A4A7161E133543&thid=OIP.A2qv-RNz_SkDjzUg8vO1hAHaDV&mediaurl=https%3A%2F%2Fwww.guyson.com%2Fwp-content%2Fuploads%2F2015%2F01%2Fsuction_and_pressure.jpg&exph=273&expw=605&q=guyson+blaster+nozzle&selectedindex=66&ajaxhist=0&vt=0&eim=0,1


Gorblimey .... wot a link ...  :headscratch:

The L/H one ( 400 ) is the gun that was fitted to mine .. Not too good a piccy unfortunately. Air up blue pipe, steel cone acts as a venturi and creates partial vacuum which sucks up air and media up t'other tube. Steel cone wears away eventually, especially with aggressive abrasive. Not so much with glass bead ..

Dave
Title: Re: Cheapo sandblaster upgrade
Post by: Graham Meek on March 12, 2019, 04:07:24 PM
Hello Gray

Thats a tidy and convenient sized blast cabinet for doing out kind of small work. Looks good, well done. :ThumbsUp: :ThumbsUp:

Do you have a sketch of the siphon bit? I cannot quite visualise your description.

What do you consider to be the better blast media and where do you recommend to buy it from?

Thanks in advance

Mike

Hello Mike,

I have an article prepared that is with the UK publishers. This gives all the details of the nozzle design and the spherical bearing for mounting the air-duster/blaster. As regards when this will be published I cannot say.

The media I use is "Suafine Shot, Sand Blasting Expendable Abrasive Grit". It has a grain size of approximately 0.2 - 0.7 mm, and despite it being called "Sand", it isn't. I bought my 25 Kg bag from the internet back in 2015, the media in the cabinet at the moment is still the first filling. I doubt I shall ever get to use it all.

Regards
Gray,
Title: Re: Cheapo sandblaster upgrade
Post by: Vixen on March 12, 2019, 04:18:09 PM
Thanks,

I will look out for your article

Mike
Title: Re: Cheapo sandblaster upgrade
Post by: awemawson on March 17, 2019, 05:52:29 PM
The problem that I have with mine, which is a full size commercial Guyson one, is the glass misting up as I breath on it - never solved this problem in the ten years that I've had it ! I suppose a heater pad would maybe do it?
Title: Re: Cheapo sandblaster upgrade
Post by: pgp001 on March 17, 2019, 06:55:46 PM
Andrew

Did you not read the bit in the instruction manual about holding your breath whilst blasting  ;D

Phil