Sandblasting prior to painting
Daniel G. Miller
sandblasted in prep for painting. There is a guy down the street from me
who does a fair amount of blasting but usually on heavy duty marine
equipment. I've had him do some smaller things before (like heater
boxes) and he's "turned down the pressure etc. for these jobs". My
question is twofold:
#1. Does anyone know the blasting pressure (or CFM) and "grit" of
blasting material appropriate for blasting paint and some rust prior to
priming and painting a bug? In other words I don't want the surface
pitted or thinned but I do want paint and rust removed and the surface
sort of etched for good adherence of the first coat of paint. I'd like
to be able to quantitate the amount of blasting power he's going to fire
at my vehicle so that there is something left when I come to pick it up!
#2. I've heard of a number of people having their vehicle blasted with
plastic beads or with walnut shells. What is the consensus opinion on
this type of surface prep. I imagine it would only remove paint, and not
do much for rust. Also I imagine it wouldn't prep the metal very well. I
also figure it would be minimally destructive to the metal.
Thanks for reading
Dan Miller
P.S. Does anyone know if WW carries L87 Pearl White?
Dave Holleran @ Nor-Cal VW's
By any means should Sandblasting be used for stripping any part of the
exterior body unless it's a bumper or something small like this.
Sandblasting will warp the sheetmetal and it will be hell trying to make
it straight again. As far as Walnut shells (plastic is too hard for
VW's) are concerened, These will work extremely well without warping the
shell of the car. Another method is Aircraft stripper but this leaves a
messy goo that you need to dispose of.
Dave.
--
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Dave Holleran
President of Nor-Cal Volkswagens car club Sonoma County, Ca
P.O. box 11413
Santa Rosa, Ca 95406
Web site http://www.norcalvws.com
My page is http://norcalvws.server101.com/mypage.html
My toys,
1965 Beetle Street/ Mostly Strip Sedan
1990 Volksubushi part VW part Mitsubushi.
Dave Holleran @ Nor-Cal VW's
Dave Holleran @ Nor-Cal VW's
johns...@sprintmail.com
is a big myth. I'm sure somebody who doesn't know what they are doing
could warp metal, but shops who know the trade will not warp panels.
I just called the shop who did my car, here is what they use:
Abrasive: Aluminum Oxide
Grit: 80
Pressure: 25 psi
CFM: 300 (no typo)
Nozzle size: 3/4"
I can assure you that NOTHING was warped on my car, and if you look at
Page 9 of my '57 Resto series, you will see that ALL panels were done.
I have seen this shop doing flimsy, un reinforced flat Americam metal
hoods with no warping.
I'm sold on sandbalsting when it comes to stripping, chemicals are very
messy, and environmental nightmare and not as thorough as sandblasting.
Just my 2 cents, posting by deja.news (yuck!) becuase my newserver seems
to have decided that it isn't talking to anyone today.
Dan M., hope you get this, let me know if you don't.......
In article <378446B4...@gateway.net>,
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Brad Gom
sandblaster on my bug and it worked beautifully. Sandblasting is the -only-
way to fully remove rust without removing the remaining metal. whether or
not you want to blast the whole body is another question. I just blasted the
rusty areas that needed to be welded and around the windows, etc. If you do
blast the whole body, you must use etching primer as the first coat, then
primer-surfacer to fill the small pits, then glazing putty or something
similar to fill the remaining low spots.
I suggest you take a door from the junkyard, or a spare fender or something
to this guy, and tell him to blast it bare. Then prime it and see how sooth
and straight the surface is.
good luck.
also- be sure to seal up the holes (like the heater pipes and all suspension
joints) before sandblasting..
Daniel G. Miller
compressor (20gal) that will put our 9 CFM at 40 PSI but that's not
enough for most sandblasting set ups (so I'm told and so I read). Most
people seem to use pressures below 40 though and I always wonder what
kind of CFM mine puts out at say 25 PSI. One of these days I'll have to
construct an air flow tube and outright measure it.
Curious how you catch sand and clean up as well.
Dan Miller
John Henry
You should see the setup the shop I use has. 3/4 of a full 55 ft
flatbed trailer. I have a 3.5 HP, 33 gal compressor (6.8cfm@90;
8.5cfm@40psi) and "blast out of bucket setup". It is OK for small parts
and maybe a rust blister, but beyond that, I take stuff to the shop.
High volume sandblasting requires massive amounts of air....
--
John Henry, the "Fweeminator"
"Yea, to roar is to have honor. But to Fweem, that is to be truly
noble"
- Unknown
Visit the "BugShop" at: http://www.geocities.com/motorcity/4000/
Dave Holleran @ Nor-Cal VW's
John,
I'll check out your images but, I still feel that Sandblasting isn't
the way to go. Plus, you used an abrasive media, Not sand. Big
difference in the two. 80 grit Aluminum oxide is a good abrasive as you
can't control the Grit quality of sand as well as you can with other
media's. The other option is having a Caustic Soda etch for the body
providing that there's a local shop to do this. A beetle body in my town
only costs $200.00 for a complete strip of every last ounce of paint on
the car.
Dave.
johns...@sprintmail.com wrote:
>
> Sorry Dave, I have to disagree. "Sandblasting will warp the sheetmetal"
> is a big myth. I'm sure somebody who doesn't know what they are doing
> could warp metal, but shops who know the trade will not warp panels.
>
> I just called the shop who did my car, here is what they use:
>
> Abrasive: Aluminum Oxide
> Grit: 80
> Pressure: 25 psi
> CFM: 300 (no typo)
> Nozzle size: 3/4"
>
> I can assure you that NOTHING was warped on my car, and if you look at
> Page 9 of my '57 Resto series, you will see that ALL panels were done.
> I have seen this shop doing flimsy, un reinforced flat Americam metal
> hoods with no warping.
>
> I'm sold on sandbalsting when it comes to stripping, chemicals are very
> messy, and environmental nightmare and not as thorough as sandblasting.
> Just my 2 cents, posting by deja.news (yuck!) becuase my newserver seems
> to have decided that it isn't talking to anyone today.
>
> Dan M., hope you get this, let me know if you don't.......
>
--
Kafertoys
6.5 hrs and 60 gal tank , i dont think i will have a problem sandblasting
anything. oh its 9.9scfm at 90psi. and 130 psi. Max
Dave Holleran @ Nor-Cal VW's
Whoops!
That's My price as I have friends in the Buisness,
A pair of doors are $75.00 retail,
Hood & decklid $75.00 retial
Body shell around plus or Minus $300.00 retail.
It's still cheaper than your location but aren't you in So-cal?
Nor-Cal Metal Stripping
Windsor, Ca
(707) 838-9470
Dave.
Dan wrote:
>
> On Thu, 08 Jul 1999 21:37:08 -0700, "Dave Holleran @ Nor-Cal VW's"
> <"norcalvw(Nospam)"@gateway.net> wrote:
>
> >media's. The other option is having a Caustic Soda etch for the body
> >providing that there's a local shop to do this. A beetle body in my town
> >only costs $200.00 for a complete strip of every last ounce of paint on
>
> this is a *killer* deal... it would be worth driving for. the
> places i've seen charge around $600 for all paint removal of a
> stripped bug; doors, hoods, etc., included.
>
> >> Sorry Dave, I have to disagree. "Sandblasting will warp the sheetmetal"
> >> is a big myth. I'm sure somebody who doesn't know what they are doing
> >> could warp metal, but shops who know the trade will not warp panels.
>
> herein lies the key. heavy-duty commercial sandblasting
> establishments can definitely warp body panels, i've seen it happen.
> they use way too much air pressure, and since they don't know what
> they are doing, they point the blaster directly at the panel. this
> increases the heat significantly. point the blaster at an angle to the
> panel if you are working with a lot of air pressure.
>
> i've done a lot of sandblasting myself, it works great. and it
> does, by the way, remove some good metal along with the rust. you will
> need at least a 6hp compressor on a full size upright tank, and then
> you will still have to wait for it to pump up... i blew thru 80 lbs.
> of sand on my van in no time.
>
> dan
> http://www.oceanstreetvideo.com
Dan
Dan
<"norcalvw(Nospam)"@gateway.net> wrote:
>Dan,
> Whoops!
>That's My price as I have friends in the Buisness,
>
>A pair of doors are $75.00 retail,
>Hood & decklid $75.00 retial
>Body shell around plus or Minus $300.00 retail.
>It's still cheaper than your location but aren't you in So-cal?
>
>Nor-Cal Metal Stripping
>Windsor, Ca
>(707) 838-9470
>Dave.
you really got me going there for a minute, dave :-) yes,
that price is from a place in the l.a. area... i'm closer to san
diego, we don't have much in the way of competitive media blasting
prices.
dan
John Henry
fenders, hood TWO decklids BOTH sides, 2 doors (not inside cavity), gas
tank and the body shell including all of the bottom, the dash, a
pillars, threshold, etc. Fenders are around $30-$35 each, front an back
ad are lids and doors. Sounds about the same as your place...
Dave Holleran @ Nor-Cal VW's wrote:
>
> Dan,
> Whoops!
> That's My price as I have friends in the Buisness,
>
> A pair of doors are $75.00 retail,
> Hood & decklid $75.00 retial
> Body shell around plus or Minus $300.00 retail.
> It's still cheaper than your location but aren't you in So-cal?
>
> Nor-Cal Metal Stripping
> Windsor, Ca
> (707) 838-9470
> Dave.
> Dan wrote:
> --
> To reply Remove the (nospam) from my address.
--
John Henry
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