Multi tank and compressor build for blasting

[brightspark]

looks like its its a suction gun .over priced and not much cop

 

[conor1n]

Good evening all,

So today I received a 90 litre cabinet and tried out some shot on a couple of parts. The setup was simply just my 200 litre 3hp motor compressor with about 9-10CFM FAD. I used a 5mm tip.

It wasn't bad to be honest. Obviously the compressor cut in early and remained on unless I gave the blasting a break.

I would be happy that by adding extra capacity and the other 3HP motor that I would happily blast parts in the cabinet... keeping the duty cycle etc in mind.

Now, for the chassis / ladder frame chassis I was thinking of doing. I have concluded that it's probably most economical to rent out a large >100CFM unit.

 

[Erie Fred]

Good evening all,

So today I received a 90 litre cabinet and tried out some shot on a couple of parts. The setup was simply just my 200 litre 3hp motor compressor with about 9-10CFM FAD. I used a 5mm tip.

It wasn't bad to be honest. Obviously the compressor cut in early and remained on unless I gave the blasting a break.

I would be happy that by adding extra capacity and the other 3HP motor that I would happily blast parts in the cabinet... keeping the duty cycle etc in mind.

Now, for the chassis / ladder frame chassis I was thinking of doing. I have concluded that it's probably most economical to rent out a large >100CFM unit.

what was the "shot" ?
Type and size.

 

[conor1n]

It was actually this stuff.

25kg Shot Blasting Grit | B/25KG | Sealey

Suitable for both handheld and recirculating shot blasters. Complies with COSHH SI-1657-1988. Not suitable for use in shot blasting cabinets.

www.sealey.co.uk

I just looked there and it said it's not suitable for cabinets.

I also have some if this very abrasive stuff which I'm not sure I will ever use as I think it's very cutting. I've not opened and might return it.

Also have some 80 mesh Garnet. Which I thin would be ok?

I should probably get some crushed glass also which appears to me the most suitable for what I want.

 

[Erie Fred]

Get as fine as you can.
it's not like sandpaper, fine will get into the deep pitted corrosion better.
finer also means more abrasive per second is going thru the nozzle.

 

[conor1n]

Get as fine as you can.
it's not like sandpaper, fine will get into the deep pitted corrosion better.
finer also means more abrasive per second is going thru the nozzle.

Ok, interesting... with that in mind.. I think that this "shot" is definitely on the finer end of the scale.

What differentiates some media from being suitable and unsuitable for blasting cabinets?

 

[dave h 2]

Ok, interesting... with that in mind.. I think that this "shot" is definitely on the finer end of the scale.

What differentiates some media from being suitable and unsuitable for blasting cabinets?

The life span of the grit.
Aluminium oxide gets smaller but stays sharp during use and when it's done it comes out in the dust extract. You top it up with fresh and you get a media that can both get into pits and still knock flakes off. Leave the little black pits around unpainted for a day or two and the rust grows out of them like spots of mould.
At the Silicosis end of things kiln dried sand is very poor to start with and the second time use doesn't make a noticeable impression.

 

[brightspark]

The life span of the grit.
Aluminium oxide gets smaller but stays sharp during use and when it's done it comes out in the dust extract. You top it up with fresh and you get a media that can both get into pits and still knock flakes off. Leave the little black pits around unpainted for a day or two and the rust grows out of them like spots of mould.
At the Silicosis end of things kiln dried sand is very poor to start with and the second time use doesn't make a noticeable impression.

if and i say iff you did use it it works very well at 90psi and cleans of well rusted car wheels no problem/ not for second use unless you like hurtling a load of dust around and get nowhere . not sugesting it mind

 

[conor1n]

Thanks everybody. While I may revisit the media discussion, I believe crushed glass is readily available and suitable for what I need.

...Oh and about needing a bigger boat. I think I will need one alright!

So initially, I plan on doing my own Range Rover and also a friends Toyota Hilux. For the Hilux it will be a cab + tub off job and blasting the frame chassis.

I am going to start off with this 20 Gal blasting pot and my proposed system of 400 litres + 18 CFM (FAD) powered by 2x3HP motors. I am well aware that this is not an ideal system. I'm trying to balance and trade off between high initial investment and not taking 10 days to blast the chassis.

I am going to build the system in such a way that it will accept a third air input. If my 18CFM is just not adequate then I can beg/borrow/steal scramble to rent out another compressor that will add to that FAD value to get over the line.

This is a trial run for a potential new business and if it shows promise I think I would invest in this 3 phase 10 HP 300 litre compressor with about 28 CFM FAD. Combined with the other two motors - that would make for (18 + 28) = 46 CFM FAD. *I would need to double check the electrical situation on that. Alternatively I would buy an ICE compressor and run it out the back of the unit when blasting.

Then there is the safety aspect of this. Below you will see an early picture of my unit and the mezzanine I referred to earlier. This mezzanine is surrounded by stud walls with offices on the other side.

If I was to build the system proposed above it would be 4 vessels (50 + 200 + 100 + 100) litres (and potentially the 300 litre 3phase). That's starting to get serious. Serious in the sense that it's a lot of air. Is it legal and/or even advisable to have this inside a workshop space?

Surely there is a case to made that these should only be run outside in some kind of shed/hut or at the very least in a cage of some sort. If so, what specs of cage are considered safe?

(Please see note after pic on what I am working towards overall...)

Overall, I am currently looking at the feasibility of setting up the capability to be able to blast and seal the chassis of 4x4 trucks ("jeeps") for clients. There was another business around doing this kind of work and they had no end to the customers coming. Long story short the guy runs a much larger business sealing asbestos roofs, and he set up the car underbody business during COVID. Between it being too much hassle for him and getting shut down due to a planning issue there appears to be a gap in the market around the midlands of Ireland where I am.

My friend with the Hilux has been trying to get somebody to do this for a while now and he says there are lads coming into his garage most weeks looking for the same service.

I'm trying to ease into this without a massive capital outlay and test the waters.

 

[Burdekin]

Ideally your line running to your filters should also be 1.5 times or more larger than the line out that feed the pressure pot or spray gun etc. Minimise restrictions in your airline. Pic of how I made my propane cylinder.

I have one of those pressure pots and great for the little jobs I do but the nozzle and valve wear quickly so you’ll most likely need to upgrade those.

If you can a diesel compressor could be the easiest solution.

Regarding expanding the business have a look into rust proofing, there’s a shortage of folk doing it up here and if you set it up properly could be a nice earner and go well with the media blasting side. These guys are a good example: https://preserveprotect.co.uk/ and have a look at dry ice blasting for cleaning the underside of cars, that’s another thing that I think would go well.

 

[Burdekin]

We use garnet, no idea why but just throwing it in the ring as a potential option.

 

[Ianb]

Sorry if its already been mentioned. Not sure if you still intend to use gas bottles, but if you are and don't want to weld fittings it is possible to set them up with a small tube to the bottom of the tank and have it come out through the centre of your fitting on the top to drain them.

Sorry don't remember specifics as it was a while ago, but sure I saw the idea on this forum.

 

[conor1n]

Ideally your line running to your filters should also be 1.5 times or more larger than the line out that feed the pressure pot or spray gun etc. Minimise restrictions in your airline. Pic of how I made my propane cylinder.

I have one of those pressure pots and great for the little jobs I do but the nozzle and valve wear quickly so you’ll most likely need to upgrade those.

If you can a diesel compressor could be the easiest solution.

Regarding expanding the business have a look into rust proofing, there’s a shortage of folk doing it up here and if you set it up properly could be a nice earner and go well with the media blasting side. These guys are a good example: https://preserveprotect.co.uk/ and have a look at dry ice blasting for cleaning the underside of cars, that’s another thing that I think would go well.

View attachment 427425

Interesting yes. I was only thinking the other day that I will try and use something decent for the "ring main".. what size did you run?

What is your hunch on cost vs benefit of a diesel compressor versus the 3 phase I mentioned above?

Thanks for input on the business side of it.. Maybe I failed to mention.. the primary objective of the blasting is to perform good rust prevention / underbody sealing as an all inclusive service.

We use garnet, no idea why but just throwing it in the ring as a potential option.

This evening I cleaned the shot out of my cabinet and gave garnet a go.. some 80 mesh. I was very happy with it.

Sorry if its already been mentioned. Not sure if you still intend to use gas bottles, but if you are and don't want to weld fittings it is possible to set them up with a small tube to the bottom of the tank and have it come out through the centre of your fitting on the top to drain them.

Sorry don't remember specifics as it was a while ago, but sure I saw the idea on this forum.

It's all good.. type away, thanks

I do intend on using and rather not weld the pressure vessel itself. I need to investigate what fittings I can use. To be honest, I would probably turn it upside down and support it by welding to the collars on top and bottom, and not the vessel itself.

 

[conor1n]

Does anybody have any leads (names or websites) for looking up fittings?

What size fittings / threads etc go into those cylinders?

Thanks a lot in advance

EDIT: Just googled and found these https://www.pipeworksuppliers.co.uk/collections/black-malleable-iron-pipe-fittings

 

[Ianb]

Here is a thread with a bit of info and photo of what I was trying to describe.

Propane cylinder water drain-Problem solved

Faced with the old problem of how to drain condensate from a propane bottle air reciever I have come up with a solution. I removed the valve and replaced it with a 3/4 BSP nipple, on to this I fitted a 4 way 3/4 BSP cross fitting. Into the top of the cross fitting I put a 3/4 - 3/8 reducer and...

www.mig-welding.co.uk

I cut the handle off mine and welded some legs to it, haven't had any problems, also gave it a coat of paint and it is hardly recognisable as a gas bottle.

It is worth mentioning that even after filling the tank with water and letting sit for a while, when you start using it the air does smell of 'gas' for a while, seems like the smell gets into the metal??

 

[Burdekin]

Interesting yes. I was only thinking the other day that I will try and use something decent for the "ring main".. what size did you run?

What is your hunch on cost vs benefit of a diesel compressor versus the 3 phase I mentioned above?

Thanks for input on the business side of it.. Maybe I failed to mention.. the primary objective of the blasting is to perform good rust prevention / underbody sealing as an all inclusive service.



This evening I cleaned the shot out of my cabinet and gave garnet a go.. some 80 mesh. I was very happy with it.



It's all good.. type away, thanks

I do intend on using and rather not weld the pressure vessel itself. I need to investigate what fittings I can use. To be honest, I would probably turn it upside down and support it by welding to the collars on top and bottom, and not the vessel itself.

I used 15 copper with a 10mm airline from the filter to spray gun but I really only spray paint. You should be looking at 22mm at least or larger I would think. Or large hose.

I have no experience paying for a diesel compressor but the benefit is plenty of air if you want to expand the business. This type of work I think you need several vehicles on the go to bring in the revenue. Cars can be at different stages of the process and you could end up employing a couple of folk so working at the same time. I suppose think of the end game a bit when looking at what's required.

Good stuff on the rust proofing business, I think it's a good idea which can be expanded.

 

[Burdekin]

Here is a thread with a bit of info and photo of what I was trying to describe.

Propane cylinder water drain-Problem solved

Faced with the old problem of how to drain condensate from a propane bottle air reciever I have come up with a solution. I removed the valve and replaced it with a 3/4 BSP nipple, on to this I fitted a 4 way 3/4 BSP cross fitting. Into the top of the cross fitting I put a 3/4 - 3/8 reducer and...

www.mig-welding.co.uk

I cut the handle off mine and welded some legs to it, haven't had any problems, also gave it a coat of paint and it is hardly recognisable as a gas bottle.

It is worth mentioning that even after filling the tank with water and letting sit for a while, when you start using it the air does smell of 'gas' for a while, seems like the smell gets into the metal??

If the guy can’t Tig weld just get someone to Tig weld on a couple of bosses. It‘s a 5min job so won’t cost much and the best solution. I washed and washed my bottle out with soapy water and bi-carb as I use it for my air fed mask, there was no smell so it can be flushed out.

 

[dave h 2]

If you go at this full time consider what happens to the dust laden air in that building .
A road drill comp does not need a tank just a BIG filter and a big hose.
Beware of farmers, dung is very corrosive and I wouldn't ever buy a Rangy from one. Expect quite a bit of extra work compared to a Chelsea tractor.

 

[Ianb]

If the guy can’t Tig weld just get someone to Tig weld on a couple of bosses. It‘s a 5min job so won’t cost much and the best solution. I washed and washed my bottle out with soapy water and bi-carb as I use it for my air fed mask, there was no smell so it can be flushed out.

Yep, not sure if it was you or not, but I did see bicarb being mentioned to remove the smell, obviously only seen it after doing mine!

 

[conor1n]

Here is a thread with a bit of info and photo of what I was trying to describe.

Propane cylinder water drain-Problem solved

Faced with the old problem of how to drain condensate from a propane bottle air reciever I have come up with a solution. I removed the valve and replaced it with a 3/4 BSP nipple, on to this I fitted a 4 way 3/4 BSP cross fitting. Into the top of the cross fitting I put a 3/4 - 3/8 reducer and...

www.mig-welding.co.uk

I cut the handle off mine and welded some legs to it, haven't had any problems, also gave it a coat of paint and it is hardly recognisable as a gas bottle.

It is worth mentioning that even after filling the tank with water and letting sit for a while, when you start using it the air does smell of 'gas' for a while, seems like the smell gets into the metal??

Thats an interesting take on it for sure, thanks for sharing. I think I am going to do what you have done with the 4-way cross fitting, but turn the tank upside down, and have the outlet with copper in yours plumbed to the drain circuit.

It's great to see the multiple solutions to the same problem on this site.. really gives you plenty of inspiration on techniques which is helpful on other projects.

I used 15 copper with a 10mm airline from the filter to spray gun but I really only spray paint. You should be looking at 22mm at least or larger I would think. Or large hose.

I have no experience paying for a diesel compressor but the benefit is plenty of air if you want to expand the business. This type of work I think you need several vehicles on the go to bring in the revenue. Cars can be at different stages of the process and you could end up employing a couple of folk so working at the same time. I suppose think of the end game a bit when looking at what's required.

Good stuff on the rust proofing business, I think it's a good idea which can be expanded.

Ok thanks yes.. I suppose what you are really talking about is a "manifold" type pipe, where you have inputs from various receivers/compressors which leads onto output.

Is the theory that this manifold should have a volume equal or greater than the sum of the total inputs on it, so it doesn't become a bottle neck? Is that effectively what you are saying.

I completely agree on the end game etc and scaling the business. Right now I am just trying to build the bare minimum capability with the least outlay to test the concept. Reality is that the blasting is just a piece of the puzzle.. and at this stage if it takes me even a lot longer to do then that's fine... while I test the market and work out a system.. if the market is there I can iterate on my system and optimise for scaling it a bit.

The diesel towable compressor is the only approach if commercially sandblasting, but the budget just isn't there at the moment and I don't reckon I need it for startup.

If the guy can’t Tig weld just get someone to Tig weld on a couple of bosses. It‘s a 5min job so won’t cost much and the best solution. I washed and washed my bottle out with soapy water and bi-carb as I use it for my air fed mask, there was no smell so it can be flushed out.

Interesting as I will have an airfed visor on the go too at some point.

If you go at this full time consider what happens to the dust laden air in that building .
A road drill comp does not need a tank just a BIG filter and a big hose.
Beware of farmers, dung is very corrosive and I wouldn't ever buy a Rangy from one. Expect quite a bit of extra work compared to a Chelsea tractor.

Absolutely. The plan is to make an enclosure for the blasting process and contain the blast media and dust. At the beginning I will either need to go slow by taking breaks to let it settle.. It's something I will have to play by ear.