What Would Be...........

[Tng21]

Right, im thinking of gettin myself another compressor early next year ( i stupidly sold mine due to lack of cash ) to blast my car engine parts clean before i start to polish them.

When i had my other compressor i was using aliminuin oxide grit to clean em down, which was great. But as ali oxide turns your workpeice into a a dull grey surface.

Of which i then have to sand back down to get the metal surface to come back through.

So my fella polishers, my question is..............


What would be the best blast media to use, that WONT turn my workpiece into a rough dull grey surface which i have to sand back anyway??

Ive been told that Glass Beading would be good for me, but i dont know what it is, or how the finish from blasting would differ from ali oxide as i cant find any video's of a glass beaded item.

SO, can anyone help and advise please.

Im pretty happy with the results of work i CAN get, but want to progress next year, finding all the right toolds, and media and stuff to set up my garage properly instead of a ****ty mess of a shed so in the near future i can get my work done quicker, without the quality suffering, so i can at some point, go full time and hopefully turn this into a fully fledged business.

[jrow]

Tng21,

Use your AO, then try some greaseless in 220 or 320 grit and then polish away!

John

[grommit]

hello Gareth,
Glass beads produce a much smoother and brighter finish than angular abrasives, and can be re used anywhere up to 30 times.as you know they come in different sizes(Mesh) course all the way to fine.As glass bead are ideal for polishing aswell you will need to experiment with different Mesh sizes,am sure the guys on here will advise still allowing no damage to the substrate.
i was up the garage today, but didnt have time to blast the reaminder of the BMW wheels, i spent my time cutting the sheet by hand for my PC oven.so i am hoping to get blasting lata this week, gotta get some AO next month.
i haven't been on MSN for a bit so hope to catchya soon.
talk to you soon m8,
Bri

[baz]

like grommit said glassbeads leaves a smoother and brighter finish then al oxide.
turning down the pressure could help too. i always try to use minimum pressure needed to remove whatever finish is on part ,if possible i try not to blast part at all before polishing (chemical stripper and a good cleaning is sometimes all that is needed)
don t let some guy sell you (crushed recycled glass)as glassbeads it is NOT the same. i ve seen this happen before

[Tng21]

Originally Posted by jrow

Tng21,

Use your AO, then try some greaseless in 220 or 320 grit and then polish away!

John

yeah but this is what i want to get away from, this is how im was doing it to start with, but after i sandblast it, im left with a rocker thats dull and grey and they have to go to greaseless to get it back to bare aliminium. Plus its still fairly rough.

The peices i do are a fairly rough to start with, with a orange peel like texture which is a pain to remove just using greaseless and hard wheels. SO i was hoping i could find a media that would get rid of the orange peel texture but leave it fairly smooth-ish. SO then the greaseless hasnt got that much work to do.

Originally Posted by baz

,if possible i try not to blast part at all before polishing (chemical stripper and a good cleaning is sometimes all that is needed)

I hear what your saying but i wanted to blast my parts as i have a fairly rough and pitted work areas on the parts i do. SO was hoping to find someone that smooths the peices out at the same time as cleaning it.

Here's a pic of the texture i was on about
in this pic you can sort of see where i have to start, very bumpy surface, which obviously have to be perfectly smooth



this pic was after i attacked it with a wire brush wheel on a bench grinder for ages, which kind of like smudged it a bit flatter to start with but done no good really.

[baz]

i never use wire wheel when polishing , at best its a waste of time and at worse
it makes deeper grooves to remove then to start with .
in theory, by blasting with fine glassbeads always on a certain angle it would remove some material from the top of the bump on the part making it smoother.
but in reality on most parts it is difficult to always blast in same direction and angle
and it would take longer to make it smooth that way compared to just taking a few minutes with greaseless

[FigureLLC]

looks like a good candidate for a vibratory polisher, no?

[grommit]

yeah figure LLC vib polisher sounds a progressive step, but tnc21's realy up against it, as all his £'s will go on other tools well b4 he can go self employed.
Gareth do you know anyone in our area with a vib polisher.No doubt you will already look at the prices of these machines and one large enough for your items.Saying that i fancied one last year, was just a case of saving up the pennies.I want to get my Enfield back together and sold so thats some more money towards tools.
got a feeling 2008 will be good m8.stick in there.
lata guys
Bri

[jrow]

Tng21,

What I think you are seeing on the manifold is the marks that the sand casting left.
I'll stick to my original post, use the AO, to get rid of the sand casting marks, but add this. After the AO use Glass Bead as Baz suggested to smooth out the profile, and then go to greaseless and polish!

John

[mpierich]

Originally Posted by jrow

Tng21,

What I think you are seeing on the manifold is the marks that the sand casting left.
I'll stick to my original post, use the AO, to get rid of the sand casting marks, but add this. After the AO use Glass Bead as Baz suggested to smooth out the profile, and then go to greaseless and polish!

John

Hmmmm...wouldn't it be more efficient to go straight to the greaseless? Just asking - maybe I lost track of something here...