What should on watch out for when taking an angle grinder under the truck to deal with rust?

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Beej

Beej

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Hey folks,

Title says it all. Of course I'll watch out for rubber. Won't go too crazy on the gas tank.

Any bolts or special fasteners that I need to pay special attention to? The diff fill and drain came to mind.

Thoughts?

Thanks in advance for any replies.

-- Beej
 
Your eyeballs and lungs.

Brake lines and fuel lines. Common sense stuff really.

Make sure you are using the grinder in a direction where it isnt going to catch and jump back into your face/arm/stomach, etc.
 
Thank you! I almost forgot I needed more than just my regular safety glasses. Ordered some goggles.
 
Sparks towards you, means that if grinder catches it will go into metal and not you.
Get some cheap welders gloves to hold on to it.
No Polyester (fleece) or nylon clothes. Cotton is good, Leather is best.
Get 3M Cubitron 2 Cut Off Wheels if you can. They are Super Mean but $$$.
 
Awesome tips! So glad I asked. Although I consider myself fairly capable around the garage, a lot of the jobs on this truck are first rodeo for me.

I don't have the tools or editing skills to video but I do plan on documenting the process with PICS!
 
3m Roloc Green Bristle discs work almost as well and are much safer. I use the 2" & 3" on a mini angle die grinder for everything now, but you can get the adapter for common 4.5" angle grinders. Ebay is the cheapest I've found.
 
A wire wheel in a Corded Drill will go a long way in knocking off rust and scale.
Make sure you wear a dust mask and junk clothes at minimum.
Cardboard is easy to move around on too.
Then Astro Sprayer and Fluid Film.
$36/Gallon shipped thru Zoro on Ebay if you buy 2.
 
Hornd said:
...
Get 3M Cubitron 2 Cut Off Wheels if you can. They are Super Mean but $$$.
Click to expand...

I'm not the most experienced at rust removal, but cut off wheels?:confused: For accessible, flat areas I use a DA sander with 60grit, tighter areas, needle scaler and/or wire brush.
 
Pin_Head said:
What's the point?

After the rust has eaten away your undercarriage, you want to grind away some more?
Click to expand...

Oh, a fella from OC, CA wants to dog me about trying to combat rust? Suppose I ought to just quit doing all maintenance because the truck will eventually die anyway?

The point is to try and keep 'er together for a few more years. This won't be an every years job. I'll grind off some rust, paint on POR15 or similar and try and maintain that but as it is now, the rust is working wayyyy faster than any grinding I'll be doing.

I'm not missing the point though. I wonder if its worth it but this is the truck I've got.

Hornd said:
A wire wheel in a Corded Drill will go a long way in knocking off rust and scale.
Make sure you wear a dust mask and junk clothes at minimum.
Cardboard is easy to move around on too.
Then Astro Sprayer and Fluid Film.
$36/Gallon shipped thru Zoro on Ebay if you buy 2.
Click to expand...

Yep. This is my plan for the more detailed work! I've got some wire wheels and a big ol' orange drill that tries to break my wrists every time I use it.

How easy to use is the astro sprayer? I don't have compressed air. Maybe it's worth renting for the day?

Thanks for all the feedback!
 
Also, to the extent there is a better way, open to suggestions. Someone recommended soda/sand/walnut blasting. I've heard of people doing this to boat hulls but never an undercarriage. Is this common?
 
make sure you don't have anything flammable under the vehicle...like paper towels soaked with liquid wrench. They will go up in SUPER big flames...from what i hear, of course.
 
I have seen my fill of rust, so I am just trying to save you time and work. With POR15, you don't need to grind off the rust. You just chip off the loose, flaking rust with a needle gun or similar and then wire brush it. Grinding is unnecessary hard work and removes good metal. Read the tech paper for POR15 and follow its recommendation.
 
Do you ever see how rust works under paint and makes a bubble? Unless you completely remove and seal rusty metal it just continues to rust underneath. The bubble just holds more moisture in constant contact with the metal, speeding up the oxidation.
This is where an oil or grease come in. It stops the rust by not allowing oxygen to get at the metal.
It is easily removed (on your clothes) and helps with removing fasteners.

A sealing paint like POR15 will trap moisture and rust against the surface.
On new metal it is great as there is no rust under it to flake it off so adhesion is good.
Price a gallon of POR15 and tell me how it compares to a $36/gallon of Fluid Film.

If you don't have air:

 
Tools R Us said:
I'm not the most experienced at rust removal, but cut off wheels?:confused: For accessible, flat areas I use a DA sander with 60grit, tighter areas, needle scaler and/or wire brush.
Click to expand...

You are correct. Cut off wheel is for cutting not rust removal.
 
OP, I trust you didn't mean to use a grinder with a grinding wheel. That is not a good way to deal with normal surface rust IMHO. Wire wheels and cups yes. A wire wheel will do a number on your eye though, so yes, good safety goggles... And a dust mask too.
 
e9999 said:
OP, I trust you didn't mean to use a grinder with a grinding wheel. That is not a good way to deal with normal surface rust IMHO. Wire wheels and cups yes. A wire wheel will do a number on your eye though, so yes, good safety goggles... And a dust mask too.
Click to expand...

3m makes a few different discs specifically for rust. I'm going to try a few of those and I have a brass cup brush and wire wheel for a corded drill as well.
 
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