Which blast media to use?

[Barkychoc]

I'm looking to use a blast cabinet (The Frost build your own version) to blast some alloy rocker covers before I get them powder coated.

I'm probably going to get the blast media from Machine Mart unless someone has a better suggestion (I'm in Nottingham).

There seems to be more than one grade - 60/80 grit and 80/120 grit aluminium oxide and also glass bead media.

I would have just bought the glass bead media but now I've seen the aluminium oxide I don't know what to go for.

All advice appreciated.

 

[shenion]

Go with glass bead. IMHO, there is nothing better for aluminum.

About anything else is abrasive. The glass bead just bounces off aluminum but shatters the brittle oxide surface.

 

[guzziguy]

yep i agree glass bead all the way for me and id probably go for the 80/120 grade,i bead blasted the wheels off my old bee em k1200rs,took a bit of time due to the thickness of paint but was worth it in the end,i used to use a bead blaster everyday @ work when i was a metal polisher before changing to welding

 

[Shox Dr]

Garnet. Works untill it's turned to dust

 

[rtbcomp]

If you're going to get them powder coated use aluminium oxide, it gives a coarser finish which the coating can adhere to. Beads are best to give a nice satin finish prior to polishing.

I use very worn glass grit then finish with beads.

Got to PKR on ebay, MM are expensive!

http://shop.ebay.co.uk/merchant/pete_booth_W0QQ_nkwZQQ_armrsZ1QQ_fromZQQ_mdoZ

 

[bigbadbugga]

I'm looking to use a blast cabinet (The Frost build your own version) to blast some alloy rocker covers before I get them powder coated.

I'm probably going to get the blast media from Machine Mart unless someone has a better suggestion (I'm in Nottingham).

There seems to be more than one grade - 60/80 grit and 80/120 grit aluminium oxide and also glass bead media.

I would have just bought the glass bead media but now I've seen the aluminium oxide I don't know what to go for.

All advice appreciated.

these guys will deliver and are miles cheaper, the link is to the abrasives application guide, have a look around the site for contact and delivery info.

http://www.hodgeclemco.co.uk/index.php?page=AB_selectionguide

oh, btw, jblast superfine is the stuff I use for all my car bits, works out at about £7 per 25kg bag IIRC.

 

[rtbcomp]

J-Blast Supafine is good, is does wear down quickly and is a bit too dusty to use in a cabinet. It's a copper slag/iron silicate.

Glass grit is about the same price, wears down but remains sharp so can be re-used (even though it is sold as a one-time abrasive)

If you're using a cabinet and doing steel bits then chilled iron is your man, can be used several hundred times, but must be kept dry and is expensive per kilo and very dense so you don't get much volume for your money.

 

[s7acker]

If you're using a cabinet and doing steel bits then chilled iron is your man

I use chilled iron for heavy rust removal on 70yr old car suspension and chassis parts and it really is excellent. The only problem I ever had was when I blasted a front I-Beam axle from a '38 Fordson and then had it powder coated.

The old commercial axles were a bit soft and the chilled iron embedded itself in the blast profile. Invisible to the naked eye but pretty obvious after powdercoating when the powder pinholed everywhere the iron was embedded in the surface!

For aluminium valve covers I tend to use glass bead.

 

[English Steve]

You had a '38 Fordson powder coated Shame on you.

 

[s7acker]

You had a '38 Fordson powder coated Shame on you.

Only the front I-beam and only because it was too pitted to wet spray! I've got another one here in slightly better shape but I'm going to do a hydraulic brake conversion using the original drums and backplates before I use it on the front of my next little project.

 

[malcolm]

J-Blast Supafine is good, is does wear down quickly and is a bit too dusty to use in a cabinet. It's a copper slag/iron silicate.

Glass grit is about the same price, wears down but remains sharp so can be re-used (even though it is sold as a one-time abrasive)

If you're using a cabinet and doing steel bits then chilled iron is your man, can be used several hundred times, but must be kept dry and is expensive per kilo and very dense so you don't get much volume for your money.

I'm just about to invest in some new abrasive - have a friend passing by Sheffield next week and could ask him to stop by Hodge Clemco.

I do find the Jblast supafine far too dusty for the cabinet - can't see a thing in there (also need to set up extraction). How much is chilled iron from them? Is G12 chilled iron about right? And how much nicer than glass grit?

I've got some alloy wheels to blast, so a bit of glass bead could be an idea. Noticed some there. What size would you tend to use?

 

[rtbcomp]

I've used G5 (£25) and G7 (£17) chilled iron, G7 is the coarser of the two. I'd recommend G7, I suspect G12 is for battleships. It's much more dense than J-Blast.

I use 801AF glass beads, 74-149 micron (£34).

All prices +vat / 25Kg

 

[malcolm]

Brilliant thanks - I had the sizes all wrong!
(for anyone else tuning in I've got a pressurised blast pot with a 3mm nozzle running from a 14cfm compressor).

Out of interest, what do you use your glass grit for?

 

[rtbcomp]

I use glass grit instead of J-Blast, it's a penny or two more expensive and although it still wears down the particles remain sharp. It doesn't need as much pressure as J-Blast, but particles can embed in softer metals if you use too high a pressure. I've got some as fine as flour and it still works with a suction gun, but the pressure pot clogs up.

With it being light in colour it doesn't darken the blastroom as much. It's also more environmentally friendly.

Although Hodge Clemco list it in their brand new revamped website, they don't actually stock it!

 

[malcolm]

Not so handy if it's not in stock. I'll stick with Jblast for outside and go for chilled iron inside. And beads for alloy. It's a pity they don't sell the cheap and dangerous blast pots any more.

 

[rtbcomp]

If you're ever down Bilston way you can get glass grit from Pete Booth, or he will ship it to customers. Works out reasonable by the ton!

It is a pity about the pots, you'd think they'd get them legit, they seemed to sell well.

 

[Wedg1e]

I use 80 grit aluminium oxide for general cleaning and glass beads for anything delicate... does mean a messy clean-out of the cabinet to change over though.
We've just bought a Machine Mart cab at work, it's used for cleaning carbon off arced high-voltage components made from ceramic. So that's a source of free glass beads for me

 

[Shox Dr]

Is this not the type http://www.transtools.co.uk/store/prod_4626/workshop-machinery/other-workshop-machinery/sandblaster-10-gallon.html


currently out of stock

 

[rtbcomp]

Is this not the type http://www.transtools.co.uk/store/prod_4626/workshop-machinery/other-workshop-machinery/sandblaster-10-gallon.html


currently out of stock

That's a pot not a cabinet. Imteresting it says CE approved, I wonder iif they'll get them back in stock.

 

[Shox Dr]

I know it is , I was repling to your post #16.


Anyway I called Transtools today, and they said the blast pot was no longer available and they had been looking for a replacement unit for sometime.