47-55.1 Removing old paint and rust

[8man]

Some more questions:

As soon as my doctor releases me, I'm going back to work on the trucks. I'm to a point on the 54 where I need to get several layers of old paint and a bit of surface rust removed so I can finish the metal work.

Here are some pictures:
These are the running boards. They are rusty, but no paint. So, I was wondering what method you all would use to get the rust off of these? Sand blast? Soda blast? Soak in something like Rust 911? I know I can't wire wheel the bottoms and do any good, so something else??
IMG_1281 by Robert Moorman, on Flickr

Here is the back of the cab. The yellow is glue from where they had glued carpet to it. Also, a couple of layers of paint under that. Same question, what method?

IMG_1284 by Robert Moorman, on Flickr

Here is the dash. I think the cab ALL needs the same treatment, but I'm not sure what.
IMG_1285 by Robert Moorman, on Flickr

The top can be sanded, it's a smooth area, but what about the drip rail? How do you get it clean enough to paint. Again, I was thinking the entire cab needs to be done. I looked into Acid soaks to get rid of rust, paint, etc., but that is really expensive, and I've heard of some issues with the paint after the acid.
IMG_1288 by Robert Moorman, on Flickr

The inside of the doors looks like this, the outside has multiple layers of paint, and I've had to repair the bottom lip on both, so they need to be cleaned up.
IMG_1286 by Robert Moorman, on Flickr

This blurry pic is the underside of the roof. They glued carpet on it as well. So it has carpet glue of some sort and rust, and with the way the metal for the windows joins the inside of the roof, how do I get that clean? How do you get into all the spaces where two pieces of metal come together, without actually joining each other?
IMG_1287 by Robert Moorman, on Flickr

I have used wire brushes on my drill and my grinders to remove rust and paint, but there are so many areas where I can't get them into. The sander won't get into all the areas either. I know sandblasting is a bad term on sheet metal, I saw what it did to the "replacement dash" I got for the 48.

So, what do you do to get the metal prepped and remove rust and paint for primer?

Thanks!

[leegreen]

Tell us what sort of final finish you want the truck to have, $10,000+ paint job or rat rod with linseed oil?
An expensive paint job may make it worth the cost to get it dipped.

I'd use a stripping disk on exterior surfaces and wire wheel on interior, knotted wire wheel where cleaning is more important than fine finish and a soft wire wheel on things like the dash. I'd wire wheel the running boards as well, no point spending more on preserving the ones you have than a set of repops are worth.
If there is existing body filler you don't want to mess up, use chemical paint stripper in that area.
The glue could be a problem if it just moves around under wire wheel, then try solvents.

Gutters and cab back seam: soft wire wheel in drill or spot blaster with a less aggressive media then soak primer and paint into both with a small brush right away before doing other body work/paint.

I'd metal prep flat surfaces before primer.
For all those hard to get to spots inside: lots of paint on a brush. For areas you are concerned will rust from behind top the paint with a waxy non hardening undercoat either commercial or home brew (hint toilet wax ring melted into non detergent oil)

I taped up all the holes and then sloshed a liter or so of paint around inside each door, letting it run down into the frames, corners and seams then letting it drain from drain holes with the doors upright and level

[8man]

Thanks Lee.

I should have mentioned that I'm a "pretty paint" guy to keep my wife happy.

[fauXGT]

Yep. Depends on the goal. Rough patina'd or $$$$ paint work.
My goal is to have a patina, and not scared to drive it.
On rust, I would convert light areas (rust prep), remove the rough loose stuff and encapsulate it (por-15), then work on replacing the nasty areas. My running boards were decent. I wire wheeled the rust (with mask and goggles), then hammered the dents. Replaced the rusty mounts. Por-15 both sides and will paint the tops black. But I'm not going perfect.
It all depends if your area has a dipping process. If not, soda blasting would be the next thing.

[mr48chev]

Soda blasting will take the paint off but won't touch anything except the loose surface rust.

Sandblasting works good IF the person doing the blasting has a lot of experience doing sheet metal and knows how to keep from damaging it. You don't want to take it to the heavy equipment shop where the low IQ guy who does cleanup around the place also does the sand blasting. Ask around and get recomendations from other car folk and that incudes getting the same name from several sources as the go to. Expect to make a road trip to get it done. Bryan isn't a hard trip from Houston, Dallas, Waco or Austin. I'm thinking the guy With the shop in Houston that does the wild trucks sends his work out to a shop in Houston. Martin Brothers out west of Austin have someone with a sand blast rig show up at their shop. I'd check to see who those shops use. This is one thing you want a known quanty on even if it costs a bit more.,

[8man]

Thank you both.

Mr48, you are right about the short road trip, so I'm looking at car resto places now to find someone.

[leegreen]

If I was taking it somewhere I'd give hard thought to dipping: paint removal, rust removal, neutralizing and then zink powder coating for primer
No idea what that would cost but it would sure be a nice boost to the project timeline.

you'd want the same sort of scouting process as mr48chev suggests for blasting before you let someone drop your cab into a vat of acid, lots of horror stories about dipping gone wrong out there

[mongocanfly]

I'm a fan of blasting..soda isnt aggressive enough, and sand is very harsh.. coal slag works very well..
If you do, make sure they know what they're doing..
Another idea would be the water based blasting.. they'll come to your house and do it there..
Then they coat it with rust inhibitors allowing you time to get epoxy on it..
As for dipping..very expensive when I checked..
and nobody local to me, which means long road trips X2..its a several day process..
Vic1947 can probably tell you..hes had several dipped
But I've also heard of leaching issues with dipping, where the cleaner seeps out and eats your new paint up..

[8man]

Thanks. I am looking into media blasting.

The acid dipping was expensive, 2,500 for the cab and doors, and it was over 3 hours each way to both of the shops I found. I also heard about the potential issues of dipping.

So now to find a good blaster who knows what he is doing.

Thanks everybody.

[mongocanfly]

Check into the water (dustless) blasting.. they specialize in autos..in your driveway

[8man]

Will do!

[gsinon]

Originally Posted by mongocanfly

Check into the water (dustless) blasting.. they specialize in autos..in your driveway

Definitely read reviews and ask around about this. Every single person I know or read that has done this regrets it. Made a huge mess in their yard/driveway and it packs deep with wet sand/mud in places that are very hard to get out.

I haven't done it, just basing this on what I have heard and seen from friends that have done it.

[R&B51]

Had a guy use walnut and pecan (plus his secret mix also had something else) and came out great. I just had him spray epoxy primer after air blast and some kind of quick rinse he used. He stayed away from large flats on hood and roof top and left those for later hand removal.
We’ll see but what he did worked great while finishing the build.
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[R&B51]

He blasted everything in and out, even giant box of parts, bumper to bumper
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[R&B51]

I think it was some kind of phosphorus rinse
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[dsraven]

if it were me I would get a quality blaster who is familiar with car blasting. not an equipment blaster as they don't normally have to worry about warping heavy castings. some will spray epoxy right away for you but remember blasting leaves a profile that looks like a mountain range if you look at it with a magnifying glass. that means unless the dude puts a super thick coat on then the epoxy will level out into the valleys and the tops of the profiles will be left exposed and can start to rust right away. i know a fella who had this done on friday and when he returned on monday it was already rusty. if you can get the epoxy on and get it home without getting wet, into a warm dry shop and then get after it with some 80 grit to knock the profile down and then epoxy it that would be optimal. when you talk to the blaster ask how many vehicle bodies he has blasted and how he does it. the thing with blasting is about not getting up too close, also staying in constant motion and blasting in a way that the media hits the surface at an angle. also ask the dude to use his big compressor line to blow out any and all cracks and crannies. inside the cab you may wanna stuff something into a few blind holes where sand will make it's way into and not be able to get back out without putting the cab upside down and blowing air into the hole, like around the windshield and the door pillar areas. when you get it home you will find it takes a lot of sandpaper to get the surface smooth unless you use something like zirconia, the normal autobody sandpaper gets ribbed off pretty quick on the bare metal. I did a whole bunch of stuff myself at a u blast it place and the problem I found was they won't let you spray paint there, environmental issue, and also when you get it home it's a lot of prep work to get done right away. you could do a bunch of small trips and do a few manageable things at a time. cab one week, fenders another, etc. that allows you to do a good job at sanding and epoxy on each part without too much time leaving the other stuff bare.

[dsraven]

https://www.sandblasterinfo.com/prev...-sandblasting/

I have also used the strip it discs with success but they can get pricey and they also wear down quick and leave a surface profile. almost anything is gonna cause heat build up, even a wire wheel, so be careful and move around so the heat gets spread over a larger area instead of concentrating in a single spot. if thinking of blasting you could help the blaster by using some chemical stripper on the glued areas as he will need to spend some time getting that off I would think. anything you can do beforehand will lessen his time spent shooting sand at your truck parts so less chance of getting warpage. like it says in the link, less pressure and a finer sand will help. some guys say crushed glass or coal works best. in my cabinet blaster i use garnet as a media that doesn't break on impact so easily so that the media can collect at the bottom and be recycled through the machine again. basic sandblasting sand turns to powder quickly so that is better for a panel because it takes some of the impact. I have a 5 gallon pressure pot blaster that I use for smaller parts. it takes a lot of air to operate and the compressor works full time to keep up. the good part is the pressure is then less so warpage worries. doing a part at a time has it's merits. blast it, prep it, epoxy it, put it aside and do the next part.

[62c30]

I've got a good blaster up here I have used a lot. They do a lot of cars and main business is stripping aircraft parts. Problem is they are always booked out for several months on the bigger items like cabs and beds.

[Stepside Jim]

When I saw the posted pics, the first thing I wanted to do was get out the sand blaster.

I have a pressure tank style that holds around 50 pounds of sand. I've used it for 40 years now. Cracks, crevices, areas that are pitted, blast and done.

I did the whole underside of my hood, carefully yes. Always moving the wand around while blasting sheet metal. The hood is black clear coat now with no sign of warpage.

Once blasted I always use Pre cleaner spray and spray til it is dripping off the metal, my plan is to remove dust residue and any contaminants. Once fully dried, on goes the epoxy primer.

Yes, wear and mask and safety equipment. I tell everyone...I hate the procedure of sandblasting, but I love the result.

One other benefit of sand blasting....I believe it leaves the best microscopic hook for primer to grab onto

Oh, one more.... Grinding, my everyday is about metal fabrication, often times my projects end with 40 grit flap discs or similar grinding. I usually use the sand blaster over the grinding marks, no more grinding scratches, surface prep done.

[dsraven]

sndblasting will usually leave behind a rough surface, enough to grab onto a wipe down rag and leave behind small trorn off fibres. it also leaves behind some small embedded particles of the blast material and a profile that is full of high spots and corresponding low spots. sure, lots of guys simply blast, blow it off and epoxy prime it, using lots of epoxy, and say they have had no issues. I am betting these guys have not left the parts outside or in an area with a lot of moisture. i say this because the high spots usually are not adequately covered so they actually stick out above the epoxy. some quick sanding with either sandpaper or scotchbrite prior to epoxy will help knock down those peaks. I have seen it, I know it happens easily and can depend on the grit of the sand used. mostly the sand is silica sand so small embedded pieces that can be unseen by the naked eye will cause pinholes in the epoxy and this can lead to issues down the road. it's like building a house, a flaw in the foundation means a lot more work as the building goes up on top of the foundation.

[Stepside Jim]

Since we're on the subject...Epoxy over sandblasted metal.

What would be applied over the epoxy that was applied over recently sandblasted metal?

[gsinon]

Originally Posted by Stepside Jim

Since we're on the subject...Epoxy over sandblasted metal.

What would be applied over the epoxy that was applied over recently sandblasted metal?

Once the parts have been media blasted and then coated with a good epoxy it needs to sit and let fully cure. After that it all depends on what the body panels need and the look you are after.

For me I will sand just enough to abraid the epoxy but not go through to bare metal. I will sand quickly with a 150-180 grit sand paper and then do my body filler work as needed. Afterward I topcoat it all with VP2050 which is a high build epoxy primer PPG sells. This product does two things, it allows me to get epoxy on any place that I broke through to bare metal again, and also has a high build similar to a polyester primer. Think feather fill but in an epoxy.

I then block the daylights out of that to get everything as flat and straight as possible. You can now topcoat that with a "normal" primer surfacer or go straight to sealer/paint as long as you didn't break through anywhere again.

30 guys will all give you different advice or how they do it. This is just mine and it has worked well for me to get show car level finishes or even just nice drivers.

[gsinon]

Originally Posted by dsraven

sndblasting will usually leave behind a rough surface, enough to grab onto a wipe down rag and leave behind small trorn off fibres. it also leaves behind some small embedded particles of the blast material and a profile that is full of high spots and corresponding low spots. sure, lots of guys simply blast, blow it off and epoxy prime it, using lots of epoxy, and say they have had no issues. I am betting these guys have not left the parts outside or in an area with a lot of moisture. i say this because the high spots usually are not adequately covered so they actually stick out above the epoxy. some quick sanding with either sandpaper or scotchbrite prior to epoxy will help knock down those peaks. I have seen it, I know it happens easily and can depend on the grit of the sand used. mostly the sand is silica sand so small embedded pieces that can be unseen by the naked eye will cause pinholes in the epoxy and this can lead to issues down the road. it's like building a house, a flaw in the foundation means a lot more work as the building goes up on top of the foundation.

This is so right on!! Most people will take a freshly sandblasted part and epoxy then paint. I've seen more issues with that process down the road then you could imagine. The freshly sandblasted part needs to be sanded and properly cleaned before epoxy goes down.

I also think people throw out the term sand blast far too often. I am having my cab and parts media blasted. Most likely using walnut and possibly another form. Sand should be used very sparingly on sheetmetal parts.

[dsraven]

-sandblast unit
-blow off to remove dust and pockets of sand left in crevices and corners. sometimes avacuum helps
-wax and grease remover wipe down to remove contaminants-this is a two rag system where one rag is super soaked and is used to apply, the second rag is used to wipe off and this one needs to be turned a lot and replaced with a clean rag as it gets contaminated. this is so contaminants picked up by the rag are not respread on another area
-scuff sand the sandblasted areas to knock down the sandblasting profile. if there are areas that were not blasted these can also be sanded and their edges feathered out. there should be no shiny spots on any painted areas
-blow off the parts to remove any dust and particles
-wipe down with wax and grease remover again to remove contaminants, allow to dry thoroughly
-apply epoxy coat using airline driers and moisture/contaminant filters etc
-repair any panels that require welding or metal work
-prep repair areas that are bare metal with sanding, wipe down with wax and grease remover and apply epoxy to any bare metal
-apply filler to any areas that require filler- this is a touchy subject as a lot of guys will apply filler to bare metal. the thought hereis that filler is porous and allows moisture to collect like a sponge and can cause the bare metal under it to start the rust program again. its a personal preference of mine to apply the filler over the epoxy for this reason
-scuff sand the entire area, no shiny spots should be showing
-wipe down with wax and grease remover
-apply high build primer over the entire surface
-block sand-apply more high build as required to level the surface using appropriate steps to ensure a proper bond-guide coat is a great idea as it shows when you have sanded all the spots. when the guide coat is sanded off then all the areas have been touched with the sander. just watch what you are doing so you don't sand through to bare metal again. guide coat will show the low spots well as the lows will stay the color of the guide while the highs get sanded off. also, a slightly different tint of high build for each application coat will show when you have sanded through the coat you are currently working on. using a long hard board with light pressure will get the best results on flat surfaces as it doesn't conform to a shape like a softer foam covered block does
-when done to your satisfaction another wipe down with wax and grease remover
-a thin sealer coat can be applied, then wait the required time between coats and apply the color etc

thats how I do it but I am not an autobody man and also haven't painted anything in a couple years. it's best to ask a paint supplier and also best to use the same brand of product through the process so you don't end up with compatability issues.

[dsraven]

gsinon is right on, the epoxy needs to cure before you start sanding on it or it will not adhere well. I use the high build epoxy primer as well.