Stubborn Rust


| September/October 2001



Smoke Stak

A recent topic on Enginads Smokstak at www. enginads. com/smokstak. cgi

Various individuals started, commented on and concluded this bulletin board thread...

Okay, gentlemen, here we go...Everyone has their own concoction for loosening rusty parts and any help would be welcome! My preference is Kroil brand oil as it has always seemed to be the best. Situation: I have two needle valves rusted in place on a carb and have been soaking them for over a month. No results? I'm afraid of putting too much tension trying to force them to open with fear they might snap off. I would then never be able to reseat the fuel jet portion, if I had to drill them out! I thought about heating to expand the metal, but we're talking about cast iron. Any thoughts? Thanks a heap!

I have had pretty good success boiling parts in water. I use a Coleman stove and an old large sauce pan for small parts. It works amazingly well on some things. I too had a carb with a stuck needle on an Ottawa engine. The boiling did the trick. I have a large hot tank for whole engines that works well to get them free and cleaned, using 3.5 lbs. of lye per gallon. I wouldn't be afraid to heat the casting with a torch, if you take it easy. I have just as good luck using the small propane bottle torches as I do the acetylene torch. Good luck; as you say, it will require lots more work if you have to drill them out. What size are the needles? Are they rusted bad enough to lose some of the dimension? Hope it works for you.

Had the same problem with a couple of Fairbanks Morse duel fuel carbs. I took a weed burner and had the part hanging on a wire, heated part slowly till it just about shimmered, then dunked it in water. After doing this three times, everything came off with no problem. But, I heated slowly and in moderation. Hope this helps.

The electrolysis method of rust removal would be perfect for this situation. Search the old methods for the process; it will not harm anything, and will go inside complicated things and between threads. It works for me, and there is no danger at all!