Another media blasting question!

[smegger]

ok so i konw blasting wont touch factory underseal so i have stripped most my vw back just some residue left, i would never let the main panels be blasted as it would warp them but i am thinking would blasting leave my floor pans perfectly clean???

O and should i get someone to do it or get a 3hp compressor and blast pot and have a go??? i want to paint at some point so a compressor will be coming sometime?

heres a few pics of how far along i am

Also i dont think i am going to be able to get some places perfectly clean by hand so would blasting be the answer? eg

So any advice on what media etc and any possible problems would be great cheers!

 

[shenion]

Regular sand blasting is too aggressive for sheet metal.

I have walnut shells that seem to work well. A 3HP compressor may not have the duty cycle to handle a decent blaster.

I like using glass bead, real mild. I do all mine in a blast cabinet, so it I don't waste media. To do something that big you will need a lot of media and set up an enclosed area preferably with filtered ventilation.

I'ld have someone do it. Let them chose the media; probably something like soda or dry ice. They can probably do it for a reasonable price.

IMHO, DIY blasting is fine for small things like parts or maybe an a-frame. Big things leave to the pros, a small blaster would take days to do what their big blasters will do in minutes.

 

[smegger]

coolio im in northern ireland so im off to see if i can find a good blaster locally, anyone happen to know one over here. It can be a bit hard to get someone who wont just used the big guns on it and destroy sheet metal?
i had a feeling it was a bit of a big job for home.

 

[fingers99]

Well, mess is an obvious issue.

But I'm not sure why you want to take it right back. Looks like you've exposed what needs welding............

 

[smegger]

want treat any rust, seems there is plenty about under the underseal, im the gona cold galv and re protect the bottom of it with epoxy mastic.

 

[malcolm]

Wow - impressed with the scraping. I'd blast it myself from there. A 3hp compressor and one of the eBay blasting pots have the real advantage of not being capable of producing enough force to bend anything. I did the 0.6mm outer panels on my Renault too.

Downside is it takes a while. And it is messy. Though anyone you chose to blast it using 200cfm needs to be really careful. See the tips page on the DIY process: http://www.mig-welding.co.uk/sandblasting.htm

 

[smegger]

I did read u guide malcolm and TBH it was what made me think i could do it myself, the fact u can blast normal panels like that is a plus for me too as i intend to strip her all to bare metal and blating is easier than random orbit and elbow grease!

3hp and a blast pot and u think it will shift this rubberised residue? I have plenty of space so could do this somewhere outside.

im a student so kinda broke could a few hundred quid kit me out? should be about to spray a bit with it too.

im really fussy about anyone working on her so would love to do the work myself must look out for a 2nd hand compressor too!

The job on the renault looks great btw!

 

[malcolm]

It is very slow on the underseal that's true. If it's lifting of if there's rust underneath it can be pushed off reasonably quickly, but it's a pain if it's stuck to decent metal - for then either scrape off the worst with a heat gun before blasting or find someone with a bigger blaster.

Though you've only got bits left so my feeeling is a decent compressor (or two coupled together) to get at least 13cfm, and a blasting pot would sort the nasty bits left over and blast the rest of the floor in a long day.

 

[rtbcomp]

I've done car panels with the setup Malcolm suggests. The 3hp compressor is the minimum size for continuous use. Get some J-Blast Supafine if you''re going to do it outside, it's good for three or four times if you sweep it up and seive it.

Walnut shells and glass beads don't etch the surface of the metal so not the best if you want to paint it.

When doing panels keep the blast nozzle at a shallow angle and don't dwell for too long on the same spot to avoid a concentrated heat buildup.

 

[jugs]

I did the 0.6mm outer panels on my Renault too.

QUOTE]

I see you got the air-con model Malc

 

[smegger]

jugs that Renault has less holes in it now that it did 2 days after leaving the factory (french rubbish )


Cheers boys ill have a look around for a compressor im a bit of a tool geek so having sandblasting kit at home seems like a good idea lol!

Anything i should avoid buying?

So ill need a 3hp compressor highest cfm i can find
one of those regulator.drier thingys
blast pressure pot
hood

 

[rtbcomp]

If you buy one of the ebay 10/20 gallon pots it will come with a hood. The hood will have a perspex lens in it, this will become opaque after a couple of minutes so cut the side out of a clear 2 litre pop bottle and tape it to the front of the lens before you start.

Make sure you get a pressure pot, not a syphon type blaster.

 

[malcolm]

I'd be inclined to pick up a proper hood. The one that comes with the 20 gallon blasters is too short and light. The lenses often unzip from the hood and I replaced mine (frequently) with new material cut from thin polycarbonate sheet.

 

[rtbcomp]

I'd be inclined to pick up a proper hood. The one that comes with the 20 gallon blasters is too short and light. The lenses often unzip from the hood and I replaced mine (frequently) with new material cut from thin polycarbonate sheet.

Finding a decent one is the problem. I got one from Northern tools (£22+P&P) but it didn't go down far enough round the shoulders and the lenses are over a £1 each with VAT and P&P. The lens holder soon tore away from the material.

I got another from Canada (£12 inc P&P) which is quite well made but ties round the neck which means dust gets in down your shirt. The stitching on the lens holder is coming loose and it's fiddly to change the lens.

The proper one from Hodge Clemco et.al. are very cumbersome and around £300 a pop.

What's wanted is something like a welding mask with a flip-up lens (for inspecting work as you go) that covers the whole head and has a fabric "skirt" attached which fits half-way down the upper arm.

 

[smegger]

guys had a very local guy recommended to me, used to motorbike and car shells, ive been quoted in round £100 to get the underside blasted and coated in zinga setting myself up for homwblasting would be tons more so i think ill give him a go with the floor pans!

 

[the doc]

Blasting car

Smegger,

Where do you live in Northen Ireland? I know of a blaster near Comber might be useful to you

 

[M@tt]

the last replay to this thread was over 15 months ago mate