Honda CX 500 Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
39 Posts
Discussion Starter · #1 ·
short of sand blasting what is the best way to get rid of rust to prep for paint. ive been all over the interwebs and nothing looks like it works real well. is it all going to be elbow grease?
 

·
Registered
Joined
·
2,601 Posts
Phosphoric acid, diluted, painted on then washed off. http://www.dudadiesel.com/ but should be available locally. Muriatic (common pool acid) will also work but not as good of a choice. Naval Jelly contains Phosphoric as the active compound.



Disclaimer: This is strong stuff and you should study up on acids before you use it.



NEVER add water to acid, always add acid to water.

10:1 is going to be fine but wear nitrile gloves.

Good stuff to have around, eats off most any rust and converts the rest back to the black oxide configuration which ends up being rock hard and will take any paint your throw at it provided you hit it with a bit of primer/sealer first.



The brake rotors on your car have already been subjected to this stuff mainly because introducing a little phosphate into the surface of an iron/steel has been a common practice for ages since it offers such a high level of protection.



http://en.wikipedia.org/wiki/Iron(III)_oxide

http://en.wikipedia.org/wiki/Iron(II)_oxide
 

·
Super Moderator
Joined
·
2,854 Posts
What is it your getting ready to paint? The tank or the frame?
 

·
Registered
Joined
·
492 Posts
Black treacle will remove rust. Just clean the part of any grease/oil, dip it in, and leave it for a day or two. It works best if left in a warm place (behind the boiler). Ketchup also removes rust. Both treacle and ketchup will remove zinc plating (from screws and such). I have used both a lot over the years.



Michael
 

·
Registered
Joined
·
2,601 Posts
If you've got small parts that Evapo-Rust stuff works well provided you're not in any hurry and rinse it off really well. If you but some get a proper sized container you can seal up it remains good and the stuff will work for quite a long time until it finally depletes itself. Harbor Freight has a lot of stores near you and they carry it in the gallon size for under $20. You can even dilute it 1:1 with distilled water to increase the volume for your chosen container and it doesn't seem to affect the results.



Just don't expect overnight miracles unless it's light surface rust, I have not a clue what's in it but I've used a lot of it for smaller parts that weren't deeply eaten into by rust and it does work well. You can't just paint it on, the part has to be totally immersed in the solution and left for a decent amount of time for it to work.
 

·
Registered
Joined
·
46 Posts

·
Registered
Joined
·
2,601 Posts
Sorry, but I can speak well for the Evopo-Rust product for small jobs.

The electrolysis method also works well if you can take the time and make the proper setup.
 

·
Registered
Joined
·
590 Posts
I like the Evapo-Rust as well.



Usually 24 hours submerged in the solution will remove surface rust.



Larger pieces can present a challange.



Stan
 

·
Registered
Joined
·
835 Posts
If you've got small parts that Evapo-Rust stuff works well provided you're not in any hurry and rinse it off really well. If you but some get a proper sized container you can seal up it remains good and the stuff will work for quite a long time until it finally depletes itself. Harbor Freight has a lot of stores near you and they carry it in the gallon size for under $20. You can even dilute it 1:1 with distilled water to increase the volume for your chosen container and it doesn't seem to affect the results.



Just don't expect overnight miracles unless it's light surface rust, I have not a clue what's in it but I've used a lot of it for smaller parts that weren't deeply eaten into by rust and it does work well. You can't just paint it on, the part has to be totally immersed in the solution and left for a decent amount of time for it to work.


I used the evapo-rust in my tank on the CB750. It had been surface rust only (no holes) so I just loaded it up with about a gallon of the stuff (diluted to 2 gal) and left for about a week - turning around every day or so. The first time I drained it - it flashed over pretty quick with a brown rust again. I guess I didn't rinse well enough (as per instructions - So, I did it again for only a 24 hour period, then, after drying, I sprayed WD-40 into the tank, never saw the flash over again. After that, for storeage, I make sure the tank is full, to eliminate any possibility of further condensation causing rust. 3 years later, and the rust remains in check, and nothing has been observed in my inline gas filter.
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top