RC Tank Warfare community hobby forum

I bought a daryl tuner's idler spring for the tamiya KT and a few weeks later (some down time and an overseas trip), I find the cast iron round blocks significantly rusted and the metal rod rusted to a lesser degree.
I tried to remove the rust using sandpaper but there's rust within the screw threads which I have no idea how to get out. Plus it's going to wear out the threads so even if i manage to remove the rust, the screws won't have much depth to "bite" on.


Not sure if i should get the schumo version or get someone to mill it out of aluminium for me.

For what they cost (I think about 90 dollars plus shipping, right?) I expect it to arrive in perfect condition. Ask for a refund, and wathever you install, please share with us. I need a better tensioner too and I dont know what to buy.

If you don't just send it back, you might want to try one of the gel type rust removers. You can get them at one of the big box hardware stores. It's pretty strong stuff so be careful using it. I can give you a specific brand but not until I go back to work on Monday. We have some stuff at the shop that works really well and we use it to remove surface rust on our steel parts.

Another option for the screws might be Scotch-Brite or steel wool. You should be able to wrap it around the screw and remove the rust from the threads without damaging them. But, like Rad said, if it was like that when you got it I would send it back.

How about an environmental friendly water soluble rust remover you can dip your hands in and not get hurt?

Look up a stuff called "EVAPORUST" it's amazing! Also WD-40 now makes a product that is damn near the same thing. Great stuff! I've used it on rusty car parts and it removes all rust without damage or nasty chemicals.

Can't beat it!

Also , after you have removed the rust , paint it with some etch primer to prevent it returning.

I wonder if Hopps #9 would clean it up for you. I would suggest testing it on the plastic before using it.

Just to clarify some questions and replies.

When it arrived at my home mid to late jan 2017, it looked fine. But within 1-2 days there was a slight change in colour in some areas. I realised it was cast iron from my emails with Daryl himself. I left it aside, thinking it wouldn't rust that fast while I sprayed some oil on it. I checked on it a few days ago and it was significantly rusted on the 2 cast iron blocks and the metal rod. The springs and screws have remained pristine.

When I said the screw threads are rusted, i meant the screw threads on the 2 cast iron blocks itself. There's also rust in the narrow curved areas on the inside, making it hard to scrape it off. I learned about evaporust but I only needed a small amount and the smallest amount I can find on amazon is a big bottle. I don't mind spending time and effort trying to sand away rust on the outside, but the inner surfaces and the screw threads are just too much work.

brown spots are rust on the threads.





I am very keen on sending it back but I am not hopeful of getting my money or anything back. US$80 for a rust magnet

Where do you live? I have some evaporust I could send you in a small bottle if you'd like. Just pay the shipping and it's yours.