F-20 Radiator installation guidance

I am replacing the rad core and both gaskets on my 1938 F-20. Got the old one off, and it appears that the old cork gaskets got a coat of permatex gasket adhesive/sealer on them....I believe it was called aviation gasket cement. You remember the kind, brown, thick, goey, and had a very particular odor to it. Used to come in a small can and the screw on lid had a brush on it. you would "paint" a thin coating on the metal gasket surfaces, and place the gasket on one surface, and it would stay in place until you put the other piece on, and got the bolts/nuts started. My job as a kid, was the "painter"......dad would do all the gasket placements. last comment, the gasket was not leaking, the core was. Core was pretty rotted at the back bottom.

I can certainly use the same stuff again, but wanted to check in here to see if anyone had any pet process. I am not a huge fan of silicone, but will listen to what people have to say before I start.

Any thoughts are welcome, as I have a full day of cleaning and painting the cast parts. I also have a couple of twisted off bolts that I need to remove which will make the process a bit longer. might flow over into a 2 day project.

I used Copper Coat on my F14 when I replaced the core on it. So far I have had no leaks. Copper coat comes in an aerosol, and the can with the brush. I like the brush better, you can get a better coat on with it.

To get the old Permatex or Indian Head gasket shellac off use alchohol. Also to get the twisted bolts out, if you have enough to grab hold of with vise grips, Use a torch to heat the iron around the bolt till it is red, then cool the bolt with ice. Put the vise grips on and start rocking it back and forth, but don"t force it. Go slow and it will work fine. I keep a small bucket of water close to cool the vise grips down.

About the twistd off bolts. That was my experience with one I was recoring. Only problem was, I broke them off flush with the cast. So, I center bored and then was using an easy out....which I promptly broke off---and then I was in deep stuff. I finally had it so goobered up that I did not know what to do. I took it to a machine shop and they finished getting the broken easy out out by chipping it. then they welded up the hole, drilled and tapped again...what fun.!!!!

I surely hope that the heat and vice grips work for you!!!! Because I suspect that you have broken them off flush also and cannot get to them with vice grips.

TW

I did forget to say if they were broke off like Tom said. When I did my 10-20 rad I got in a hurry and thought the inside upper bolts were rusted solid and had the nuts on the inside of the tank. I didn"t know they went into blind holes and were loose. I cut them off with the torch which left them sticking up. Mine still had the lard oil on the threads from the factory and they all came out ok so I was lucky. Did another one where it had been apart before and it was stuck tight, so better to coat the new screws with lard oil or heavy assembly oil when putting it together incase you have to pull it apart in the future.

Thanks guys. The broken bolts are relatively easy. I bought a good left hand drill set, and I have torches. I ususally heat them up, and start with a 1/8" drill, then go up a size or two, just below the tap/drill size for the hole. 9 times out of 10, using the left had drills, when the 2nd size goes in, it "catches" just as it it coming out the other side, and backs the broken bolt out. I also heat them well, and let them soak with blaster overnight before I do the process. Worst case, I use the correct drill size for the tap. drill it out, and re-tap the hole.

I use a center punch to get the drill started as close to center as possible. One last note for those of you who use "easy outs". You need to be relatively close to the bolt size before you start. One mistake that a lot of people make is using too small a hole and easy out. that is why they break off. Drilling the hole close to the bolt size not only heats up the bolt, but disturbs the threads a bit when it cools. In fact, if you just start to see the sharp edge of the threads, you can usually just clean it out with a tap. Key point is to locate the center of the hole, and use a center punch to keep the 1/8" drill from "walking".

I am really interested in hearing about what to use on the new gaskets, and castings. I am having the castings boiled as we speak, so they will be clean and rust free when go to reassemble.

I do appeaciate everyones input

This is a great idea. A little tension and if they do not move, then clip the heads off and disassemble it. THEN for sure, you can get heat to it and the pliers!!! I wish I had thought of that...I will do it on the next one...will save a lot of pain.