VCCA Home Forums TECHNICAL - GENERAL Body - Sheet Metal, Paint & Wood Grit (silicon sand) for removing rust and paint?

What silicon sand grit is recommended for removing frame rust and paint down to bare metal?
Our local hardware store carries #60, #30 and # 20 grit.
Thank you in advance

D@C

I normally use #70, you get the job done and a nice surface as well.

Brufce

32confederate
Not sure they sell #70 but will look for it.
Ace has #100 lbs bags of 60 grit.
Thank you for the advise.
Im going to rent a diesel compresssor and sand blaster unit and spend the day taking it down to bare metal.
Inside, outside, underneath.
Any recommendations? what should I put on it after?
Thank you 32, quick reply. Your great!

Keep the blasting nozzle moving and only close enough to remove paint and rust, with a large sand blasting unit. You really need a supplied air respirator hood that is sucking good clean air. Sand and silicone are very bad for your lungs! Don't hurry and take short cuts to save rental money! It will probably be more than a day's work. I also like to use a huge or several blue tarps on the shop floor or driveway to catch as much of the used sand and debris as possible. I hang some tarps on the wall of the blasting stall splice and hang them with duct tape. If you are gonna use your shop, sand goes everywhere. remove anything or use a double or tripple layer of duct tape to cover any rubber or body tags or stuff you don't want blasted. Glass and stainless or chrome is shot with only a glanceing shot of sand.

I like to spray at a 70 degree or less angle so the sand does not spray back in my face, you also take less chance of warping the sheet metal panels.when the metal turns gray MOVE! Also if you need to stop blasting for more than a few hours (in good low humidity) Spray the area blasted with good dry air get sand and rust out of the seams and then with a primer-sealer filler good heavy one coat. Don't spray on any spray protectant containing silicone, it is too hard to remove and primer or paint won't stick good enough.

Whatever you do don't prime bare metal with straight primer and expect the metal to not rust, even inside a building.

Use an epoxy primer like DP-90. The only stuff you could put straight on metal with out a problem, don't know about the current DP-90LF. Last time I talked with the paint shop they said to use a wash material. I would talk with your local paint shop and tell them what your doing.

I've done two frame over the years. First one was with DP-90 and then a black lacquer. The other one would be DP-90 and black urethane signal stage.

Thanks Mr.Mack
Greatttttt advice.
I will be doing this in the drive way, using traps
and a painters respirator mask(is this adequate?)
Thinking about using walnut shells for the abrasive media?
The quoted price for having his done was $1800
and the one day rental is $250 plus material.
figured I could do the work. Clean the frame and remove
the black lacquer paint?

DP90 was replaced by DP90 LF (lead free)

Ok, My reply was considering doing the entire car insde and out, not just the frame, the frame should be a piece of cake and good for using epoxy primer. then whatever top coat you want enamal or Laquer. A lot of the hotrodders just wire brush the worst rust and crud off and spray on POR 15 (Paint Over Rust 15). many of our guys don't like POR 15. It is a bugger to clean up and it has some storage issues.
Outside I would use a good full respriator with a purple (particulate) cartrige. I have used them around RA materials and Silicone dust have had good results,....... or rent a good sandblasting helmet hood with a built in respirator.

You are right about that! I won't allow the stuff in my shop.

POR 15 is Crap! Have you ever tried removing the crap?

Well, no I haven't tried to remove POR15, if you think about how hard it is to remove, that may be one of it's better points..Just don't put it on where you might want to remove it!

POR 15 is a single stage urethane paint. Like every other coating it has some great properties and some limitations. If properly used, handled and applied it performs well. However if not properly used it can create problems.

I have used POR 15 successfully for over 10 years and love it. The fact that it is really tough to remove is one of its best properties but also makes it imperative to handle and apply it properly.

I have only purchased two quarts in that 10 years and am still using paint from the second can. Since the coating is a single stage paint it is cured by atmospheric conditions, in this case by water. So keeping water away from the uncured paint is critical to long term storage.

POR 15 is not UV stable so either needs to be used in areas out of direct sunlight or with limited sunlight or top coated with a UV stable material. I have several carburetors that were painted with POR 15 over 10 years ago that still look good even though they have been subjected to gas, oil, heat and other atmospheric chemicals.

The key is to understand the limitations and benefits and then use a product that maximizes the benefits and avoids or manages the limitations.

Do it right or don't do it!

with MrMack!

Mr Mack..
Help me out with your last sentance.
What is meant by dont spray just straight primer?
Can you help explain. All the other advise was fantastic
BTW.
Thank you

dac

Use a primer with sealer, you can buy primer with sealer and high filler or add a sealer to standard primer. standard primer alone will let the raw metal underneath rust if it gets any moisture from rain or otherwise on the primer, it will go thru the primer, since primer is pourous. The high filler allows a thicker build up of primer and fill minor scratches and pits in the raw metal, it helps the sanding operation.

Gotga, thanks. Yes Ive used Dupli color with medium filler.
Mr. Mack after a $375 dollar estimate on the sand blaster rental. I ended up going out and getting a used 60 gal. 7 hp air compressor ($250) and a new eastwood portable 15 gallon sand blaster (($140). I also got 10, 100 lbs bags of #60 grit for the media - silica sand. So Im ready to go. I will also get me several tyveck suits, and the resp. with purple breathers. I think Im ready to go, now I need some low to no humidity days. Since Im in Az. that wont be long. Thanks for all the advise VCCA members. Nice this bunch!
#046380
DAC

Yep, now you are not limited to rental time. Sounds like you are going in the right direction! Watch that the sweat off your nose don't drop all over the fresh raw metal!

Mr Mack
I tried sandblasting one of the rear fender wells today, and it didnt got to bad. I use the # 60 silca sand from Ace hardware, used most of the 100 lb bag but recycled 80% of that.
One problem I need help with is "moisture"!!!!
I have a small campbell hausfield air regulator and air filter on the compressor and another small air filter (bleeder) on the sand blaster, but I noticed the nozzle got clogged up multiple times. WHAT IS THE BEST SOLUTION FOR trapping condensation from the tank?????

I use a regulator and water seperator that is a commercial unit from Ingersol Rand, it has 3/4" pipe connections that I reduced to 3/8' for my airlines for blasting and painting..

moisture can be the most frustrating issue when sandblasting-aluminium compressors can become h2o pumps on humid days vs cast iron-traps in line(which can be drained),filters and separators are a must and must be drained frequently(especially compressor).If not plumbed properly- a 30cfm rental will overcome many problems-be careful when choosing medium for different metals-black beauty for heavy metal-glass beads or walnut shells for sheet metal and most of all be patient-this is not a fun job but necessary unless you can afford acid dip and remember to prime asap. I believe Tip sandblasting supply can explain better than I-good luck