Hey guys, I've read about all the ways to replace my plugs, with nickels, with brass, etc. But I have an issue with the holes. I pulled my plugs as two of them were seeping and one had a catastrophic failure. I tried cleaning the holes out with a pick and a wire wheel on a Dremel. But it seems like the steel plugs that were in there rusted to the block. I can't come close to getting a clean hole with a ridge. My thought was to use the Dremel and grind them out but I'm not sure how to keep a perfect circle. Or do I use a large drill bit, but then I lose the flat "shelf". Any advice based on my horrible descriptions?
I expect the connection between the old plugs and the block is not metal to metal, but steel/rust/iron. I'd use a little die with that Dremel to grind away the steel and hard rust, being careful not to get into the iron. Tiny die, low speed, then wire brush. Install nickels. Seal behind them with Ultra Black.
I'd use a brush not a grinding tool. Once you cut into the casting you can't reasonably put it back. Be patient.
Use an old wooden broom handle!
I'm not being a wise guy this time. When I was a little guy we were on a trip in our 22 and a freeze plug blew out. With the help of an old mechanic my Dad used a section from a broom handle to plug the hole and continue on our trip. He kept talking about doing a permanent fix but never got around to it. I'm sure it was still there when he sold the car!
More proof that "There is nothing more permanent than a temporary fix that works!".
Patience is one thing I have learned with this car. I pulled it out of a barn where it sat in storage for over 40 years and started daily driving it. Turns out that's the best way to find its deficiencies. I get to drive it for about a week then order parts to fix what broke.
My worst case scenario was pointing me toward the wood plug or tapping it and putting in pipe plugs if I ground off too much.
Use a bit of the edge on a small cold chisel, find a good edge on the steel piece that's rusted in, and with a couple of wacks you should better be able to see what you are doing as the steel/rust begin to separate.
I have used an ice pick a few times cleaning those out. Scrape into the corners, and occasionally tap lightly on the ice pick handle with a small hammer.
Worst case solution; up to and including 1913, Ford tapped them 1/2" NPT and used socket head pipe plugs This works well!!!
wire wheel, scrape or pick. mine were messy and not a great shelf. you can decide if you want to use sealant as well. I did use nickels for fun but had one leak a bit. I pulled the nickels and tapped for pipe plug to be done with them. you still need to be gentle doing that as the block can still be less than perfect. use the female plugs if you try it. always a judgment call on what you are comfortable with. good luck.
After a century of coolant working on the inside, I expect a lot of these blocks have thinner walls than what they started with. I'd be very wary of trying to tap those holes.
Even after you get the holes clean there may be rust pits or other surface irregularities. That's why I suggest using a sealant. I first tried old time Permatex that's been around forever, and it didn't do well. So I did the job over with Ultra Black, and so far there have been no leaks.
I consider the expanding of the plug by flattening the "dish" only a mechanical attachment/method of retention and use a sealer for actually sealing it. Maybe a brand new block could be sealed by the plug alone, but I think the use of a sealer would be prudent even in that case.
You only need about two threads of engagement to obtain a leaktight seal at the atmospheric pressure we are dealing with. I've done it several times with NO problems. Socket head pipe plugs are quite available and essentially sit flush with the outside of the block when properly installed. Hey if you can get the original style to seal, then great!! If not, then this is a viable solution
Yep to Les. I did mine. I will agree with Steve that they are soft and crusty which is why only suggest if you are comfortable. As Les says, you only need a few threads with atmospheric pressure and you are probably only going to get a few. Be careful and don't go Kong on it. They are NTP. Nickels are neat, but you might check the sealant suppliers for a recommendation. I won't begin to try to offer a suggestion, as that is a whole can of worms. Good luck.
I would try a bit of heat using a small oxy-acetelyne welding tip concentrated in the flange area of the hole. Any rust will pop loose and break down long before the cast iron. Heat it up a bit, let it cool, then try picking/scraping the area. If that doesn't get all of it out, repeat as necessary. Just don't try to melt anything. JMHO Dave
I used heat and was able to get most of it broken away. But the rust was still stuck in the corners and wouldn't allow the nickels to sit level. So I cracked out the Dremel. I took my time using a stone grinding tip. The cylindrical one that has squared corners. The old rust blew out in a black dust and chewed through real easy. Once I got to block material the sound and feel of the grinder changed so I was able to back off.
I was only going to do the front two as they were the only ones leaking. But the first two went so well I decided to try the back one. I placed the screwdriver I was using as a punch against it and it pushed right through, I didn't even need a hammer! I guess I made the right move.
On the same issue of frost plugs I made a set for my Studebaker where the flange had rotted off. They are somewhat larger, however they could be made smaller. The components are made of lead and stainless steel. The large washers are filed or cut to fit through the hole then turned 90 degrees. The lead plug is sized to fit in the hole and cover the outside, an "O" ring is fitted on the flange to seal. A dab of sealant is put on the 5/16 bolt to seal it as well. I used two pieces of 1/4" plywood with holes cut with a hole saw to match the two sizes, nailed or glued them tightly together to form the mold. When tightened up the "O" ring squeezes against the block and forms a water tight seal.