Painting over media blasting

[Jwright]

I Have just shot blasted my car chassis with aluminium oxide media. Do i need to remove all residue from the media prior to primer paint or is removing the loose material with compressed air and a brush enough?

 

[MetalMonkey]

You would want to get the material clean to get good adhesion for any primer. I always use panel wipe, but you may find it difficult if it is a very rough finish - cleaner the better though.
For primer, I'd suggest epoxy.

 

[ajlelectronics]

I Have just shot blasted my car chassis with aluminium oxide media. Do i need to remove all residue from the media prior to primer paint or is removing the loose material with compressed air and a brush enough?

You need to clean the surface with a solvent wipe, which will also remove anything left behind. Then two coats of epoxy primer, but watch out for temperatures as you shouldn't really be doing it under 15C if you want it to cure.

 

[Jwright]

You would want to get the material clean to get good adhesion for any primer. I always use panel wipe, but you may find it difficult if it is a very rough finish - cleaner the better though.
For primer, I'd suggest epoxy.

I don't have any panel wipe, but since it's back to bare metal would thinners be suitable? I have got some jotun epoxy primer at the ready.

 

[ajlelectronics]

I don't have any panel wipe, but since it's back to bare metal would thinners be suitable? I have got some jotun epoxy primer at the ready.

Not thinners. Get some slow panel wipe ideally. IPA might do and in cold temperatures, brake cleaner might also do.

 

[Jwright]

Thanks for the advice. Will have to see what I can source, can't think on any local stores that would stock this kind of stuff.

 

[ajlelectronics]

Thanks for the advice. Will have to see what I can source, can't think on any local stores that would stock this kind of stuff.

You must have body shop suppliers around?

 

[Jwright]

Just know of one In the area, but got to be an account holder. Think I should manage to order through someone I know.

 

[marlinspike]

5 litres for £22 on Amazon if you're not in a great rush.

https://www.amazon.co.uk/Litre-Panel-Wipe-Degreaser-S2002/dp/B006CGNY7M/ref=asc_df_B006CGNY7M?mcid=0826ec2e6ee33dd89e95b12b6c14df6a&tag=googshopuk-21&linkCode=df0&hvadid=697259790400&hvpos=&hvnetw=g&hvrand=6087492336601522099&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9046616&hvtargid=pla-858907725284&psc=1&gad_source=1

 

[marlinspike]

Well thanks very much, Amazon. Due to their algorithms and viewings, the price is now £26 so not worth bothering with. They shoot themselves in the foot sometimes trying to gouge an extra few quid out of customers.

£19 delivered at Metalflake.

 

[marlinspike]

Edit. Ignore the Metalflake price. It came up on Google search as including postage but in fact doesn't.

 

[Ross365]

I've never used "panel wipe" for anything. Searching Google to find out what "it" is, there seem to be quite a few different ideas; some water, some IPA and perhaps some surfactant.

When choosing a cleaning liquid, it helps to know what the contaminant is that you want to remove. So in the case of media blasting, it's likely to be dust rather than any form of grease, so some combination of water and IPA should do.

For wiping down before painting, I quite like white spirit.

 

[brightspark]

cant see any point in using pannel wipe or any other wipe after blasting and done properly . compressed air to remove any dust and bits of media that may drop out on the paint

 

[DaveB]

cant see any point in using pannel wipe or any other wipe after blasting and done properly . compressed air to remove any dust and bits of media that may drop out on the paint

Well if your certain no oil is in the air used for blasting that might be ok.

And did you handle the blasted surface with clean gloves ?

 

[brightspark]

Well if your certain no oil is in the air used for blasting that might be ok.

And did you handle the blasted surface with clean gloves ?

i hardly think id use a comp that chucks out a mist of oil and i wear gloves for blasting thats what filter regulators are for one on the tank and one on the pot

 

[W.olly]

I dont ever bother to clean the blasted product. just get rid of the dust if any and paint,. just done all my susoension and steering and its stuck on that hard it wont blast off. I tried a new paint and is cracking stuff. POR15 infact.

 

[optima21]

I tried a new paint and is cracking stuff. POR15 infact.

POR15 I was trying to use that 25 years ago, some people think its good, it didnt work for me, seems that epoxy primer is more highly rated these days especially if you have a less than perfect surface.

 

[W.olly]

POR15 I was trying to use that 25 years ago, some people think its good, it didnt work for me, seems that epoxy primer is more highly rated these days especially if you have a less than perfect surface.

I dont understand why it works for some folk but then others not. All i can think of is the manufacturing or application

 

[MetalMonkey]

cant see any point in using pannel wipe or any other wipe after blasting and done properly . compressed air to remove any dust and bits of media that may drop out on the paint

After blasting metal if I use panel wipe on a cloth it will come back black like coal on the first wipe, and take at least a couple of wipes before its clean. The less muck you are painting over the better in my view. I've always use it when doing any bodywork.

 

[ajlelectronics]

After blasting metal if I use panel wipe on a cloth it will come back black like coal on the first wipe, and take at least a couple of wipes before its clean. The less muck you are painting over the better in my view. I've always use it when doing any bodywork.

I fear that we are wasting our breath!