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Old 02-20-2017, 11:47 PM   #1
Rm58
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Sand blast verses grinding and wire brush on grinder.

Just starting my first rusty truck project. Replacing or patching the normal bad stuff but undecided on the rest of the truck. Putting body on another frame so I just the body. Not afraid of work and want long term fix. Any input or guidance from of you with real experience. Thanks in advance.
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Old 02-21-2017, 04:47 PM   #2
Foot Stomper
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Re: Sand blast verses grinding and wire brush on grinder.

You have to remove any loose material by any means possible. This is a must. If you can scratch, scrape, sand, pick or wiggle any debris off of the surface keep scratching, scraping etc... Media blasting is the most expensive but for a reason. It reveals the true condition of your truck, saves you much time and is the most effective way to remove all rust.

If you can see rust and can't get it off, that's ok.

Make sure you use a 2 part epoxy primer as soon as you're done scraping. There are many good epoxies out there so don't hung up on brand, just make sure it's not a "generic" brand such as ProForm as was used on this truck before I purchased it. (it had to come off!!)

The door picture is after being media blasted. Visible rust is OK. Obviously there's some work to do on the door before painting, but it is ready for epoxy primer.
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Old 02-21-2017, 05:14 PM   #3
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Re: Sand blast verses grinding and wire brush on grinder.

Thanks for the info think I'll use the media blast have done a little grinding and sanding still very messy and very labor intensive.
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Old 02-21-2017, 09:17 PM   #4
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Re: Sand blast verses grinding and wire brush on grinder.

I've had good luck with using aircraft paint stripper on the big flat panels on the doors, hood and fenders staying away the seams that the stripper could get into.

Then a typical sand blaster can be used on the "edges" like the door jams and such.
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Old 02-21-2017, 09:19 PM   #5
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Re: Sand blast verses grinding and wire brush on grinder.

My old truck has done paint but mostly patina. But thanks
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Old 02-22-2017, 08:12 AM   #6
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Re: Sand blast verses grinding and wire brush on grinder.

I think media blasting is the best method, but used improperly, can have adverse effects.. Read the sticky here in the paint and bodywork forum on repairing sandblast damage.. So you'll see whats ahead in the remote chance that some stretching of your metal does occur. Some thoughts on media blasting....

Most damage occurs from too much pressure using too large a media. Your blaster should be using low pressure, media 80 grit or finer, and spray from an angle to decrease impact..

Many times those structures surrounding openings in doors, hood and trunk undersides, etc. will block media blasti hitting the blocked area. Someone working aggressively to remove paint from an underhood structure, for instance, may inadvertently cause a stretch in the outer skin as you are blasting the hood skin inside the opening, directly next to an area it is blocked. This may cause a buckle/stretch that is noticeable due to the immediate start/stop of media blasting due to the blocked skin. sometimes it helps to block off these openings in underhood structures or inner doors to prevent this from happening (using cardboard or duct tape or??) , and sand those areas by hand..

If your media blaster happens to mention the stretching is caused by heat, run fast, run far. The stretching is caused by the peening action of the media being slammed against the metal. (think of thousands of tiny hammers hitting your truck) Any stretching has long occurred when the heat shows up, heat is a side effect of the peening process. Increase the size of the media, it's like using bigger hammers. Use too much pressure, it's like swinging the hammer harder.

Get references from people that have taken car/truck parts to them, not barges...
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Old 02-22-2017, 10:41 AM   #7
Rm58
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Re: Sand blast verses grinding and wire brush on grinder.

Great info thanks so much I'm not completely unfamiliar with blasting but was misinformed about what caused the damage. Thanks
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Old 02-22-2017, 11:21 AM   #8
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Re: Sand blast verses grinding and wire brush on grinder.

Here's a picture of my hood that was media blasted with a water soluble particulate. Smooth as a silk! The cab received a sand media but much skill was used but did have a smooth but slightly rougher surface. (The lighter colored band across the back of the cab is a lead repair done by an unknown but very crafted person)
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