more reasons *not* to sandblast your car ... Options

[SirAndy]

getting tired of my rants about sandblasting? yes? well, too bad because here is:

another reason *not* to sandblast your car !!!


pic of the rear wheel bearing from the trailing arms we just took off my car. you can hear the sand crunching inside when you turn it by hand ...
(IMG:style_emoticons/default/icon8.gif)

i HATE sandblasting ...
(IMG:style_emoticons/default/headbang.gif) Andy

[bondo]

Hey... that picture is in PERFECT FOCUS!

Who are you and what did you do with Andy?!?!?! (IMG:style_emoticons/default/biggrin.gif)

[Sammy]

That's a sealed bearing (or least it's supposed to be sealed).
Theoretically if it were in good condition the sand would not hurt it because the seal would keep it out, but sometimes theory and reality are not the same.
Probably the bearing was probably on it's way out already and the sand helped it along in a hurry but i guess it is possible the sand could have eroded the rubber seal causing it to fail.

I agree though, sand gets everywhere and is a PITA to get rid of.

[PRS914-6]

That's a sealed bearing (or least it's supposed to be sealed).
Theoretically if it were in good condition the sand would not hurt it because the seal would keep it out, but sometimes theory and reality are not the same.
Probably the bearing was probably on it's way out already and the sand helped it along in a hurry but i guess it is possible the sand could have eroded the rubber seal causing it to fail.

I agree though, sand gets everywhere and is a PITA to get rid of.

Sand at the velocity that is used will blow past seals and anything else. Same as a high pressure washer. Seals are not designed to take that kind of abuse. Only to keep grease in and dirt out at very low pressure. Sand will blow into your wiring harness looms, connectors, bearings, hidden areas, etc.

Only way to media blast is with a stripped chassis just the same as you acid dipped it. In my case I sent it in with all the 914-4 rolling gear and now that it is blasted, I am installing all the rebuilt 911 stuff so it was never an issue.

Personally, I like blasting despite the extra cleanup work. It leaves a perfect etch for primer in difficult to reach nooks and cranny's and takes a lot of work out of the preparation. If it was a race car, I would re-think that. I have mine media blasted by American Stripping using a patented media process. They use a multi step process. Not cheap. It gets rolled out of the media booth and gets epoxy primed minutes later. No moisture involved, immediate metal sealing! My painter insists on the sealing issue. (he's really anal about this stuff but very good). From start to finish, my painter won't use any liquids. Won't even wet sand!!.

I do understand Andy's grief though, it can be a real mess to deal with. Preperation and plugging any holes with rubber plugs really helps but plan on hours of vacuuming and blowing (you won't get it all) . Rebuilding anything left on the car is a must. No matter how good you mask, it gets blown in.....

[Sammy]

The single angle lip seals on that type of bearing will seal tighter under pressure, until the elasomer sealing surface is eroded from the sand. Then the sand will get past the sealing surface.
Still, bearings don't like sand; sealed, shielded, or open design it doesn't matter.

[davep]

Umm, that arm doesn't look sandblasted Andy. (IMG:style_emoticons/default/smile.gif)

[Eric_Shea]

Umm, that arm doesn't look sandblasted Andy

He left his suspension on the car when he had it blasted.

Only way to media blast is with a stripped chassis just the same as you acid dipped it.

(IMG:style_emoticons/default/agree.gif) If done properly, my preference is media over acid. Baking soda seems to be the best, followed by sand. It (sand) has to be done by someone who knows what they're doing. A lot of guys do the high pressure quicky job and the get sand everywhere and ruin panels. Gotta watch out for that.

Advantages I see in media are:

* Not having to cut the frame/backbone/longitudinals of your 914 to salvage the heater tubes.
* No acid weeping from the seams months later.

My 66 911 weeped for quite a while (over a year) and another club member here had his 914 done in the Bay area and I saw the seams weep on that for months after the dip and subsequent "neutralizer". This netted in an additional 10 hours of hand sanding.

IMHO if anyone is serious about restoring a car, the chassis should be prepped properly, as Paul mentions, and a good soda blaster should be found.

[PRS914-6]

Before and after shots of media blast.
(IMG:http://www.sayegh.org/Paul/914/914pics/Img_0103.jpg)
(IMG:http://www.sayegh.org/Paul/914/914pics/IMG_0148.JPG)

[Eric_Shea]

(IMG:style_emoticons/default/smilie_pokal.gif)

[alpha434]

Sooooo.... For future reference, just don't sandblast the wheels while they're on the car.

[Bruce Allert]

I agree though, sand gets everywhere and is a PITA to get rid of.

I didn't do any blasting on a vehicle but I did take my wife's camcorder to the beach. (IMG:style_emoticons/default/alfred.gif) By the end of the day the camera shut down & was giving an error message. Took it to the shop to see WTF...

When the shop called back they asked if I was at the beach.

So now my wife has a new camera. Couldn't be repaired for the cost of a new camera!

.....b

[SirAndy]

Sooooo.... For future reference, just don't sandblast the wheels while they're on the car.

s u u u r e ... (IMG:style_emoticons/default/blink.gif) how about, in the future, you read a post first before you answer? (IMG:style_emoticons/default/biggrin.gif)

i never said that "the wheels" were sandblasted. like mentioned above, the whole car was blasted and i left the suspension on the car so it could be rolled around.
as far as i know, the blaster never even came close to the wheels, as the trailing arms and the wheels did not show any signs of blasting ...

my point is simple, that stuff get's in *everywhere* but does not come out nearly as easy as it get's in.

in fact, just in the last 2 weeks, i ended up using the dremel to *make holes in my car* just to get the trapped sand out of it.

that is, almost FOUR years after the blasting ...
(IMG:style_emoticons/default/icon8.gif) Andy

[JPB]

Either palletise the biotch or don't sand blast at all says the man! I say sandblast? Whats that?

(IMG:style_emoticons/default/beer.gif) MMMmmm Por15.