Texture on alloy help pls

[Noods]

Hi All..

I working on a pair of old cylinder heads which are cast alloy, some of the surface has this lovely pitted finish to it, probably from casting I guess.. Other areas either don't have it or it's worn away..
It's for a show bike I'm building and would Like to know if anyone has any idea how I could achieve the pitted effect..

And no I do not want to paint it in hammerite hammer finish thank you..

Much appreciated thank you..

N@@DS

 

[langy]

Vapour blast will give tat effect

 

[Noods]

I've tried it several times and by different methods too, but it leaves it a smooth satin finish.. Which this time, is not really what I'm after..

 

[MattF]

Centre punch with the end ground to the shape of indentation you want and then stipple the metal with that. It's a time consuming method though.

 

[brightspark]

quite easy. mask all the parts up that are machined and blast it with expendable grit then bead blast it 1st blast cuts in to the metal beadblasting peens it all over and seals it still giving a uniform cast efect

 

[langy]

I've tried it several times and by different methods too, but it leaves it a smooth satin finish.. Which this time, is not really what I'm after..

You could just media blast then with something like crushed glass

 

[brightspark]

this was done with sand 1st then beadblaSTED

 

[Noods]

What type of sand are you using... Kiln dried? Eg patio sand..

 

[brightspark]

What type of sand are you using... Kiln dried? Eg patio sand..

yes that was kiln dried but if u wanted a deeper pit u would need medium grit laid on at a fairly high pressure 1st. your best bet is do a couple of test pieces 1st on some scrap ally

 

[Noods]

When you say medium grit? What is that please.. I've got plenty of compressor power..

 

[brightspark]

this is it its pretty much like crushed gravel and would cut in to the ally at high pressure i have a load but your not local otherwise u could have had some http://www.scangrit.co.uk/?page_id=81

 

[Noods]

Ok friend I'm not one to be beaten I will hunt some down..

TY N@@DS

 

[brightspark]

Ok friend I'm not one to be beaten I will hunt some down..

TY N@@DS

as i said try some on a scrap piece 1st and u wont be disapointed. it does need beadblasting after u have blasted with any sand or grit though