Am thinking of having my frame powder coated, but the frame I have is anodized aly, will they sand blast that off or coat straight over the top?

Is sand blasting an aluminum frame a no no?

If it's anodised then you don't need to get it blasted just sand it lightly to give the powder coating a keyed surface

They will probably sand blast it which should be fine.

Ken its the anodized finish that bothers me with it, its really rough textured, I did think the coating would go on over it but rekon it would affect the finished result without being removed or flatted off first.

I have spoken to the place I got in mind, he has a chemical dip or a blaster, so guess its in good hands, I cant get the price to match the £30 I have seen quoted on here but £55 sounds reasonable enough.

Just got to choose my colour..

If it's a rough finish then the powder coat will stick to that like poo to a blanket. If it's too rough though the final finish may be affected

Try and avoid chemical dips. To remove anodising you have to use IIRC caustic soda which you really don't want sloshing round inside your frame