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will stevenson

Air abrasive system

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will stevenson

High guys, I’m thinking of getting a small prep system to keep me occupied as I have some stuff to prep:), however I need to keep it cheap, preferably under £200, so far this is what I have, for £99 I have a compressor with stats of

 6L

OIL FREE

 1.2KW

1.5HP

6.5CFM

4000RMp
 116PSI 

 

and an alloy steel pen needle (£40)

 

3800rpm 

Frequency 0.28CFM 

Air consumption: 0.08(m³/min) 

Working pressure: 90Psi(maximun) 

Pen diameter: 18mm 

Pen length:155mm 

Air inlet size: 1/4" 

Weight: 135g 

( This has the appearance of an air scribe)if I just want to do light prep is this the right tool though, could I use it as air abrasive for fine details  and aside from some dolomite and aluminium oxide, what would I need, to be honest I’ve been very confused despite doing research as up till this point I’ve just used a dremel and pin vice so I’m slightly out of my depth here, any help welcomed:P (btw all this stuff is brand new as I don’t want anything dangerous)

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will stevenson
51 minutes ago, Kane said:

Hm... With a working pressure of 90 PSI, I do wonder if a 6 litre tank will be enough, or if it will be constantly running to catch up. 

 

If you are doing abrading, you will likely need a lot more than just the compressor and air eraser. Think of the dust you'll be kicking up. Will you have a dust capture system to protect your lungs and the rest of your home? A blast box, with a shop vac attached? Air line desiccant to keep the blast medium from caking in your lines? A binocular scope with a Barlow lens if you will be working under magnification? A reliable / adjustable lamp?

 

An air compressor setup with scribe and/or abrader is going to run you a lot more, methinks... :unsure:

Hi kane yes forgot to mention this, i considered getting the 25 litre version but essentially, i am maximising space as i will be storing it in a cuboard when not in use, also i will be doing it outside as the only available area for prep is not suitable to implement proper ventilation into, i was going to modify a fish tank i had lying around and open a side away from me so the dust could dissiapate, i would not be creating incredible amounts of dust, i will only use it to remove a couple mm of matrix on different specimens, the rest would still be done with pin vise, i shouldnt be running the compressor for more than an hour or 2 and i have picked one that is reported to be reasonably quite, all i think i will need more is a proper aspirator and goggles (allready have noise cancelling headphones  (i can listen to music:P) ) as health is always first priority, however the one thing (apart from magnification which i will consider) i hadnt thought of on your list is an air line desiccant, if there are two many extra parts too add or if this setup i had in mine just isnt competent, I understand and i will just save a little while longer and sell a few bits and bobs:D

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jpc
54 minutes ago, will stevenson said:

 i would not be creating incredible amounts of dust, 

Hate to tell you, but yes you will.  These machies MAKE a lot of dust.  They spray it out at almost supersonic speed.  It does not take too many minutes of air abrading before you have a LOT of dust.  You really should get some sort of dust collection.  A shop vac will work but they are loud and also not meant to run for extra long periods of time.  Like the air compressor.

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will stevenson
2 hours ago, jpc said:

Hate to tell you, but yes you will.  These machies MAKE a lot of dust.  They spray it out at almost supersonic speed.  It does not take too many minutes of air abrading before you have a LOT of dust.  You really should get some sort of dust collection.  A shop vac will work but they are loud and also not meant to run for extra long periods of time.  Like the air compressor.

ok i will look into it, 2 questions:

is there a portable one that isnt too large

probably sounds stupid but could i use a hoover (vacuum cleaner):heartylaugh:

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will stevenson

oh also some more q's on the compressor @Kane, is 0.28 cfm enough, and if i plan to use it at around 40 psi, will it be fine to turn on and off intermittently 

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hadrosauridae
16 minutes ago, will stevenson said:

oh also some more q's on the compressor @Kane, is 0.28 cfm enough, and if i plan to use it at around 40 psi, will it be fine to turn on and off intermittently 

.28 CFM?  Thats not enough for anything.  The smallest tools will use at least 1CFM, so that compressor cant even maintain with a 100% duty cycle which will kill any but the most robust (and expensive) compressors.  Honestly, 4CFM would be the bare minimum I would suggest and you also need a decent size reserve tank.  The little things made for airing up car tires cant handle the work load of trying to prep with.

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will stevenson
1 minute ago, hadrosauridae said:

.28 CFM?  Thats not enough for anything.  The smallest tools will use at least 1CFM, so that compressor cant even maintain with a 100% duty cycle which will kill any but the most robust (and expensive) compressors.  Honestly, 4CFM would be the bare minimum I would suggest and you also need a decent size reserve tank.  The little things made for airing up car tires cant handle the work load of trying to prep with.

oops i miss did the facts not sure how i got it that for of .. it is 6cfm, how long would the 6 l tank handle that at 30-40 PSI?

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hadrosauridae

The 6CFM is plenty for small air abraders and scribes, but the 6L tank is really small and will probably still be running a lot. I would suggest at least a 20Gal tank, but I understand you are trying to work with a small space.

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Ptychodus04

Not to discourage your desire to get into a higher level of prep, but trying to go super cheap only costs more money in the long run. It can also have an unexpected consequence, making you not want to prep. With the setup you are describing, you will be fighting it the whole time and will become extremely frustrated.

 

If you are going to run a small air scribe, a compressor running at 90psi and around 3cfm with a 20L tank is the smallest you can use with any success. You will still have to stop every 5 minutes or so to let the compressor catch up (not a good scenario). You can’t run abrasive with something this small.

 

No matter what you do, you are going to generate a lot of dust that is detrimental to your lungs. Anything 3 microns or smaller will work it’s way deep into your lungs. Eventually, this will kill you. You will end up with silicosis or pulmonary fibrosis (or both). My father worked in a foundry when I was a kid. It was only for a couple years but the silica dust he was exposed to in that time killed him 30 years later. It’s a bad way to die, don’t take dust lightly.

 

You must have a P100 rated respirator, ear plugs (don’t underestimate the damage to your ears from the compressor and scribes!), eye protection, magnification, and lighting at the minimum. If you move inside, add dust collection.

 

You mentioned using a Dremel. Have you tried their electric engraver? It is a decent way to edge into mechanical prep without the full expense of pneumatics.

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will stevenson
1 hour ago, Ptychodus04 said:

Not to discourage your desire to get into a higher level of prep, but trying to go super cheap only costs more money in the long run. It can also have an unexpected consequence, making you not want to prep. With the setup you are describing, you will be fighting it the whole time and will become extremely frustrated.

 

If you are going to run a small air scribe, a compressor running at 90psi and around 3cfm with a 20L tank is the smallest you can use with any success. You will still have to stop every 5 minutes or so to let the compressor catch up (not a good scenario). You can’t run abrasive with something this small.

 

No matter what you do, you are going to generate a lot of dust that is detrimental to your lungs. Anything 3 microns or smaller will work it’s way deep into your lungs. Eventually, this will kill you. You will end up with silicosis or pulmonary fibrosis (or both). My father worked in a foundry when I was a kid. It was only for a couple years but the silica dust he was exposed to in that time killed him 30 years later. It’s a bad way to die, don’t take dust lightly.

 

You must have a P100 rated respirator, ear plugs (don’t underestimate the damage to your ears from the compressor and scribes!), eye protection, magnification, and lighting at the minimum. If you move inside, add dust collection.

 

You mentioned using a Dremel. Have you tried their electric engraver? It is a decent way to edge into mechanical prep without the full expense of pneumatics.

Don’t worry all input is appreciated, I was considering getting an electric engraver but I wasn’t sure which sort to get, any recommendations? I would definitely get the protective gear as I know of the dangers of dust, sorry about your father. If I didn’t use an air scribe but used an engraver for most removal, what would be the minimum tank size for say an air eraser (also how effective are air erasers)

 

9 hours ago, hadrosauridae said:

The 6CFM is plenty for small air abraders and scribes, but the 6L tank is really small and will probably still be running a lot. I would suggest at least a 20Gal tank, but I understand you are trying to work with a small space.

I think the max size I could feasibly have is 25l which is nowhere near 20 gallons, how bad would this be

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hadrosauridae

Buy the largest and best you can afford / fit for now.  An electric engraver would be a good solution for starting out.

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Ptychodus04

I haven't used an electric engraver in about 20 years, so I know less than nothing about which ones are better. I also have not first hand knowledge of the Paasche Air Eraser. I believe @Kane has used one.

 

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will stevenson

The paasche one is a bit expensive though, more than the compressor at around £150

3 minutes ago, Ptychodus04 said:

I haven't used an electric engraver in about 20 years, so I know less than nothing about which ones are better. I also have not first hand knowledge of the Paasche Air Eraser. I believe @Kane has used one.

 

 

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hadrosauridae

do a youtube search for fossil prep engraver.  There was a person who tested a handful of different ones and talked about the good and bad of each and which one was best.  The person is from UK, so the brand names may not be identical, but I think I've seen the identical ones in the US under different names

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will stevenson
35 minutes ago, hadrosauridae said:

do a youtube search for fossil prep engraver.  There was a person who tested a handful of different ones and talked about the good and bad of each and which one was best.  The person is from UK, so the brand names may not be identical, but I think I've seen the identical ones in the US under different names

I’m in the uk so that’s great thanks I will look it up

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jpc
4 hours ago, Ptychodus04 said:

Not to discourage your desire to get into a higher level of prep, but trying to go super cheap only costs more money in the long run. It can also have an unexpected consequence, making you not want to prep. With the setup you are describing, you will be fighting it the whole time and will become extremely frustrated.

 

Ptych and I both do this sort of work professionally having started out as hobbyists (I am assuming you did, too Ptych).  This is the best piece of advice on this thread.  

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Ptychodus04
2 hours ago, jpc said:

Ptych and I both do this sort of work professionally having started out as hobbyists (I am assuming you did, too Ptych).  This is the best piece of advice on this thread.  

Yes sir, I did. I also made some of the mistakes I try to warn against. I personally found that DIY often costs as much as a purpose built piece of equipment and doesn't function as well. Currently, the only 2 things I use in my lab that are DIY are the lab itself and the blast cabinet. :default_faint:

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jpc
5 minutes ago, Ptychodus04 said:

Currently, the only 2 things I use in my lab that are DIY are the lab itself and the blast cabinet. :default_faint:

Me too... more or less.  

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Bob Saunders

I do not own an air scribe yet, but their is one brand of scribe used and reviewed on YouTube that you should read the users comments below. Vendor does not have any replacement  parts. I have used an air die grinder and the compressor at the center runs out of air shortly. I believe that a lot of folk use the Dremmel brand of engraver. 7,200 BPM. beats per minute, and they can have a short life at least in hard in hard matrix. 

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will stevenson

@jpc @Ptychodus04 @Kane @hadrosauridae so I was planning on using a trusted brand of compressor (I don’t know if I’m allowed to say their name) and a decently reviewed air eraser whilst using a fish tank I have lying around as a blast cabinet and I will sort out dust and water extraction at this point I’m still under £250 mind you haven’t totalled in any safety equipment so probably take that to £300, I will buy an engraver for larger amounts of matrix removal, what more would I need as realistically I cannot spend more, even as is I am having to sell a lot of stuff (:, actually I have an idea, Should I ask on the sales forum if anyone would trade or sell left over second hand stuff that could be trusted to still be in good condition as that might be a lot cheaper

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Ptychodus04

Don’t forget the filter and desiccant for your air line. 
 

I’d post your request on the sales forum.

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hadrosauridae

I know you are trying to work within your budget.  You could definitely get by with an electric engraver, but since you are trying to set up a full system, I dont know that you can do it for your price limit.  I built what I think is an absolute minimum system with 4CFM compressor on a 20Gal tank, air filters, desiccant, distribution, abrasive system, blasting box, dust handling and a single air scribe.  Most of this, from bargain-price chinese tool sellers and it STILL cost me $1000 (at least) to set up.  You could save a couple hundred by using a paasche air eraser, but you are still going to almost triple your budget.  Your idea of using an old fish aquarium isnt going to work.  Youd be better off just working on a bench outside.

 

I want to edit to add the whys for all this.

Your air tools are going to be using 1-2 CFM, especially a scribe, as its running at pretty much full pressure.  Even an air-abrassive which runs at lower pressure is going to drop the pressure in a 6L tank in a few seconds causing your compressor to constantly  run.  Your compressor needs to rest so much for every minute of running, and it shouldnt run more than X number of minutes without a rest.  Now the specifics change from maker and model, but if you violate the duty cycle, you will kill the compressor VERY fast.  And then the $$$ spent on it is lost.  Compressors also turn air humidity into liquid water.  Sometimess not until the hose out of the tank to your tools.  If you dont have water removal filters, you WILL begin blowing water through your tools and all over your fossils.  Beyond the water filters, you need a drier (desiccant) before your micro abrassive or high humidity levels will soak into your abrassive causing it to clump and clog.  Maybe a paasche isnt bad with humid air, but I cant say for sure since I dont use one.  If you are working inside YOU MUST HAVE a dust collection system or everything in that room will quickly become coated in abrassive dust.  This means you also have to have a blasting box that will let you use a dust collection system, and an aquarium isnt  going to work.

 

I'm not trying to discourage you, I absolutely love prepping out my fossils, and I'm sure you will too.  I just want you to have all the facts and go about this the right way so you dont throw away money.  Spend a lot of time researching and reading everything you can on fossil prep lab design and setup.  I spent months researching lab design, compressors and air handling and home shop dust systems.  I re-designed my system dozens of times before I actually began buying components.

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will stevenson

I think I can post this but feel free to say if not, i did some research today and I found this setup that is reasonably cheap. if I got this and a decent air compressor (25-50L) I have my eye on one that has water vapour removal but I think this set up has most of what I need, what do you think @hadrosauridae @Ptychodus04, this and an compressor could still cost me <£400

41C90C05-E7B5-4282-9943-FCF99EA25DC7.jpeg

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jpc

We have a few of these at work.  We bought them from a guy who made them and is now no longer in business, so not from Vaniman  They work OK, but I am afraid they don't last nearly as long as the more expensive machines.  The air pressure regulator was the first to break on all four of our units, and now we use a wrench to adjust pressure.  You will need to buy an oil filter removal wrench to take the cover off.  It is simply inpossible to take it off by hand after it has been pressured up and subsequently unpressured.  There is not enough space to get your fingers around the lid for a good grip, and it seals on there very well.  It works with fine bicarb and dolomite, but not with coarser grain bicarb (which we use in our bigger machines).  I think that the kitchen grade is fine enough, but you will go through a lot of powder so best to find a supply of 25 pound bags, if possible, or whatever is available in the UK.  It also works much better when the powder level is above three quarters full, so we fill them more often that the tank size implies.  It also needs to be clamped to the tabletop, as they do not stay vertical on their own very well.   

 

In short, a good cheaper version, and if it is what you can afford, then go for it, but now you know.  

 

Here is a similar wrench to the one we have

https://www.lowes.com/pd/Hopkins-4-5-in-Steel-and-Plastic-Adjustable-Wrench-Individual/1000730082?cm_mmc=shp-_-c-_-prd-_-sol-_-google-_-lia-_-146-_-moweraccessories-_-1000730082-_-0&store_code=1539&placeholder=null&gclid=EAIaIQobChMI58-Wjua96AIVAo9bCh3UiwaZEAQYBSABEgIdX_D_BwE&gclsrc=aw.ds

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