Plastic blasting ??

['Cuda Hunter]

So,  I found someone, finally, that will blast my car with something other than sand.
He uses plastic beads.  A metal worker I know is hooking me up with him.  And that might mean a good price as well.
  So, I am going to borrow my friends home made rotisserie, and probably use the plasti guy. 

My question is, how well does the plastic work? 
Should I be concerned when he is spraying the quarters? 
Is this as effecient as other medias?

[MoparCar]

Generally plastic will not remove rust. A lot of the top notch blasters will utilize a mix of plastic and other media at the same time in areas not prone to warping to remove the rust.


Wes

[MoparCar]

cudahunter,
I forgot that you were from Colorado the same as me. Blast-tek (tech?) in Denver has a pretty good reputation for blasting with plastic and mixes of other materials. I did mine myself in a homemade plastic "booth" in the garage because it would have been difficult to transport on the rotisserie, but I believe they were about a $850-$1,000 for the whole car. Plastic on the panels and starblast on the frame/underside.

Wes

['Cuda Hunter]

Thanks,

 I will look into that.  I will talk with the guy in Canon City and see if he has comperable technique and price.

Did that price happen to include the inside of the car or was that just the entire outside of the car.

[MoparCar]

Sorry-can't remember if the inside was included. The drivetrain was not. (rear, K, etc.)
Wes

[Topcat]

I used paint stripper on the outside sheetmetal on mine. Then sanded it with an electric sander with 80 grit. Followed by a metal phosphorous cleaner. Scotch brited, then Epoxy primer.

Why? Because after doing the underside of my car with Aluminum Oxide, I began to see how much media was beginning to accumulate in hidden areas like in the frames and wheel wells. I tried to keep it to a minimum. No matter how hard, it found ways to be stubborn to blow out.

Media takes forever to get completely out (if ever) and its not worth risking getting it into your paint once you do begin spraying. Plastic media doesn't penetrate rust areas very well either. So I see no benefit in plastic media on the outside. 

Some claim "you must media blast the entire body." Well I don't agree.

['Cuda Hunter]

Thanks TopCat.  I appreciate your experience and will consider that.

Stripper is what I used on my 67 LeMans GTO.
My main problem with it is the mess. 
It sure did cost alot less though. 

 

[MoparCar]

I used a variable speed Makita 8" buffer with 80 grit to remove everything on the fussy panels like roof, doors, fenders and then blasted the rest in my homemade booth on the rotisserie. Using the buffer worked very well and with a slow speed will not create the heat that warps. Finish off with a DA sander and you're good to go.

Topcat is right on the media---I still have media coming out of crevices after a year and a half but very little left at this time.

Wes

[pywell]

I just took our challenger in. it is a2 stage setup, they use the plastic beads whichalso helps keep the great down so warping does not occur. The 2nd stage is aluminum oxide, this will get at the rust. I was told that it is now illegal here to blast with sand because of carcinogens(sp). I saw a 69 judge and a 70 nova all done there. I also asked about cleaning etc... They said they have a very thurough cleaning process.will have pics mid january when I go pick it up.

['Cuda Hunter]

Did you get a total cost quote?

[pywell]

Did you get a total cost quote?

They are by the hour, have no clue what it is going to be, just that they're work is suppose to be perfect.I will put up pics and info when I get them.

[MoparCar]

I was also told it would be by the hour and the amount of material. They gave me the ballpark number but that was it. They also asked if I wanted any bondo/filler removed and other things like that. They would not attempt the rally hood on my Challenger which is a good sign of a shop. That sheetmetal is pretty thin and they said it would be too easy to warp it.

Do as much as you can to make it easy on them and the cost will be less. If you know you need new quarters, cut out the big sections so they can get to the wheel tubs, etc. (brace it if you are cutting a lot away) Take a good look at your car before taking it and determine what sheetmetal will be replaced in the resto process and exclude those areas from the blast. Use some spray paint or something to indicate the areas not to blast.

Wes

[pywell]

My guys just called me back and said the car was done!! Of course I did a lot of pre work to it so that they would not need to do anything but blast it. And I asked about the hoods and their reply was that the media blast they use doesnt create heat so it helps and they do hoods all the time its not an issue. I also do the undersides of hoods myself with a protable gun system to get ride of the underhood rust. I guess you have to make sure they know what they are doing, a shop that does restorations for cars/trucks should be able to do the entire vehicle without damaging anything. We pickup the car tommorow so I will bring you guys picks here when I get it home!

[Topcat]

And I asked about the hoods and their reply was that the media blast they use doesnt create heat so it helps and they do hoods all the time its not an issue.

Media blasting doesn't create heat. The sheetmetal warping effect is because the media acts like hammers hitting the same place over and over again. A repeated blasting in one concentrated spot causes the molecules in the steel to want to move out (or Away) of the pressurized area.

If you know about media types, angle of attack, correct distance, proper overlapping; you can media blast outer sheetmetal without warping.

The problem lies in that most that DIY and have warpage is because they have the damn thing turned all the way up and are moving too slow or are too close.

[pywell]

Lol, sounds about right. Expensive way to learn.