do you guys do this work on your back?
What should on watch out for when taking an angle grinder under the truck to deal with rust?
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do you guys do this work on your back?
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- #22
There's a joke there somewhere.
I hope to avoid holding the grinder over my chest looking upward because I don't want to cut my head off if it slips. But yeah, basically on my back is the plan.
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- #23
What if one ground away rust, painted, and then sprayed Fluid Film? That looks like the trifecta to me.
POR-15 sticks to rust better than clean metal.
No cut off wheels, we're not bobbing the frame.
I wouldn't even be using a grinder, wire brush the spots after a decent degreaser & slap on the POR-15.
Not sure if the user was meaning to spray sparks towards you "in case the grinder bites" - sorry, I disagree. All that crap flung at you is nasty, when we use grinders we always try to discharge away from us, and also not onto the guy working next to you in the shop. Not sure what that person meant TBH.
No cut off wheels, we're not bobbing the frame.
I wouldn't even be using a grinder, wire brush the spots after a decent degreaser & slap on the POR-15.
Not sure if the user was meaning to spray sparks towards you "in case the grinder bites" - sorry, I disagree. All that crap flung at you is nasty, when we use grinders we always try to discharge away from us, and also not onto the guy working next to you in the shop. Not sure what that person meant TBH.
B, if you do want to remove the rust, an abrasive pad of sorts or a flap disk will indeed remove rust (and clean metal for the latter) but I had better luck with steel wire brushes on a grinder. They remove the rust fast but do not much affect the clean metal underneath, which is what you want, and give you very good control. It even gives it a nice finish, unlike a grinding or sanding wheel.
A brass wire brush on a drill won't do much, though, I think. Get both a coarse and a fine steel wire cup and similar wire wheels -rated for your angle grinder speed- and you are set. Even if your paint of choice claims to work fine right on top of rust, you will want to remove the looser rust at least and the wire cups are great for that.
A brass wire brush on a drill won't do much, though, I think. Get both a coarse and a fine steel wire cup and similar wire wheels -rated for your angle grinder speed- and you are set. Even if your paint of choice claims to work fine right on top of rust, you will want to remove the looser rust at least and the wire cups are great for that.
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Not necessarily true. If the rust is killed with something like phosphoric acid, then sealed from oxygen, it will be dead. Can buy expensive paint mixtures or get one of the phosphoric acid mixtures, treat and then top coat. The two step process is often less expensive and can produce better results, at the cost of convenience.
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The key is; for the seal (top coat) to be solid, the base material has to be solid, so brushing/scaling/sanding needs to be done to remove any loose stuff, get to a solid base. Rust causes pitting, by needlessly grinding all of it out, the metal is thinned, weakened more than necessary.
knock off what you can, grinder with wire wheel etc, etc..soda blast, sand blast etc then Ospho Ospho Rust Treatment - Since 1947 NAPA has their version also... them POR 15 or the equivalent NAPA has their version of this also....
I have never "killed-it", and I have taken rust down to bare metal. Is Naval Jelly Phosphoric Acid? The majority of rust repair jobs end in more rust. I seriously doubt it is cheaper than $36 a gallon and done in 30 mins for an entire chassis but carry on.
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- #33
Thank you very much for this. With all the info in this thread, I think I'll probably plan on using the overkill method and do everything. In reality, I'll do a mediocre job on most of it and then just keep it wet with fluid film or old motor oil and hope somebody up there likes me.
I can say that my abrasive discs arrived today so I'll be testing those bad boys.
I also like the idea of the cup brushes for the grinder.
Your damn fingers.
Needle scalers are pretty sweet but I wouldn't want to do my whole frame with one, especially if a lot of it isn't thick rust (and especially if you don't have a compressor that can keep up with high CFM air tools-- big difference between airing up tires or running an impact and running air tools like this). I'd get a wire wheel for an angle grinder and maybe one of the cup styles. Any paint left over will kinda gum up most flap wheels, especially the thicker under coat. A combination of angle grinder and needle scaler would be sweet. I would not use any grinding discs. The green finger wheels are pretty sweet too and probably safer but I'd probably go wire wheel still.
I've done a ton of this on my 80... a ton... I've probably committed any number or every number of safety violations while grinding but... especially for someone new and using a grinder under a vehicle in tight spaces (which is the hardest):
Be careful of the clothes you wear. If a grinder kicks back you don't want it wrapping up your sweatshirt hood strings. I'd probably get a faceshield and wear goggles or safety glasses under that. A half mask respirator would be ideal for this as well with the flat filters but at least use a cloth face mask. -- Nothing like black snot and hacking up crap. Gloves are always good. I have a bunch of scars from grinding discs and flap wheels... Wires fly everywhere so you're sure to get one stuck in your arm if you don't wear sleeves or in your eyes if you don't wear a face shield/glasses. OH and grinding discs and other crap, can and DO blow up. I've had a cut off wheel explode and a chunk puncture an aerosol can across the shop. Other people have had that s*** puncture their face. I've also heard of grinders kicking back and running up peoples clothes and getting wrapped up and against their face. Shoot the crap away from you and be careful how you use the grinder on angles or it will want to kick.
I've done a lot of grinding and very often not taken any safety precautions because I'm in a hurry and the worst that's happened is a few pieces of s*** in my eyes and some scars and that was lucky and stupid, it only takes once to lose an eye or two... I also know people who have gotten metal embedded in their eyes. It begins to rust and they have to "drill" it out.
Get a fan if you can to blow on you while you grind.
Also, grinding dics will chew up the surface, they dig in, hard to do any clean work with them.. Flap discs work best if you want to do some finer grinding, they CAN grind down thick stuff and leave a very nice finish, they're easy to work and it's hard to take off too much material unless you try -- they don't deal well with thick paint or other crap though. The finger wheels and wire wheels mostly don't remove metal and leave a nice finish.
FWIW I'd probably rather mechanically remove the rust than try chemical means if the rust is widespread and significant, myself...
ALSO, a drill or even a die grinder air tool, etc... are no comparison to an angle grinder.
I've done a ton of this on my 80... a ton... I've probably committed any number or every number of safety violations while grinding but... especially for someone new and using a grinder under a vehicle in tight spaces (which is the hardest):
Be careful of the clothes you wear. If a grinder kicks back you don't want it wrapping up your sweatshirt hood strings. I'd probably get a faceshield and wear goggles or safety glasses under that. A half mask respirator would be ideal for this as well with the flat filters but at least use a cloth face mask. -- Nothing like black snot and hacking up crap. Gloves are always good. I have a bunch of scars from grinding discs and flap wheels... Wires fly everywhere so you're sure to get one stuck in your arm if you don't wear sleeves or in your eyes if you don't wear a face shield/glasses. OH and grinding discs and other crap, can and DO blow up. I've had a cut off wheel explode and a chunk puncture an aerosol can across the shop. Other people have had that s*** puncture their face. I've also heard of grinders kicking back and running up peoples clothes and getting wrapped up and against their face. Shoot the crap away from you and be careful how you use the grinder on angles or it will want to kick.
I've done a lot of grinding and very often not taken any safety precautions because I'm in a hurry and the worst that's happened is a few pieces of s*** in my eyes and some scars and that was lucky and stupid, it only takes once to lose an eye or two... I also know people who have gotten metal embedded in their eyes. It begins to rust and they have to "drill" it out.
Get a fan if you can to blow on you while you grind.
Also, grinding dics will chew up the surface, they dig in, hard to do any clean work with them.. Flap discs work best if you want to do some finer grinding, they CAN grind down thick stuff and leave a very nice finish, they're easy to work and it's hard to take off too much material unless you try -- they don't deal well with thick paint or other crap though. The finger wheels and wire wheels mostly don't remove metal and leave a nice finish.
FWIW I'd probably rather mechanically remove the rust than try chemical means if the rust is widespread and significant, myself...
ALSO, a drill or even a die grinder air tool, etc... are no comparison to an angle grinder.
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the phosphoric acid treatment works. Used it several times. Removes the rust, maybe some submetal too, and you make iron phosphate. It's like a rudimentary parkerizing process. Normally used with oiling afterwards I imagine. I think you'd have to choose paint judiciously to cover the phosphate coating. Maybe epoxy?
I would use acid lying under a truck very very carefully...
I would use acid lying under a truck very very carefully...