Brass Flare (?) fittings

[AHa]

Hey There,

 

I am attempting to reassemble a 1911 Buick race car and keep as much of the original patina as possible. I knew I would have leaks once I put gas in the tank, and I don't know near as much as I once did and never did know as much as I thought I did, but oh my gosh. These are 100 year old fittings, still, they should, at least in theory, tighten up and hold, right? I'm thinking there used to be something like plumbers putty that could be slathered on the fitting to help them hold once tightened. Got any ideas?

Edited March 18 by AHa (see edit history)

[Matt Harwood]

What kind of fittings are they? Single flare is pretty common in pre-war cars. If they're not sealing, you can get little copper washers that will provide the crush surface and should conform to the shape of the fitting, even it it's a bit deformed and damaged.

 

 

If they're standard compression fittings with ferrules, you can get new ferrules that should fit and as long as you're using new tubing, they should seal. Stainless can often be difficult to seal properly but if you work with it a bit and get it seated properly, it should be OK.

 

Do NOT use any kind of goop in compression fittings, it should not be necessary and probably won't be effective anyway. The threads have nothing to do with the sealing process, it's all on the seat or the tubing.

 

 

Edited March 18 by Matt Harwood (see edit history)

[mechanician]

They are probably flare fittings, rather than compression.  May even be solder-on ends, a type of union more or less.  Anyway, I have both types still holding after more than a century.  Keep them clean and they should still seal if they aren't physically damaged.  Don't seal the threads as the fittings don't seal on the threads, they seal on the conical surfaces.  I would lightly clean the mating cones with fine scotchbrite and wipe or blow them clean.

[AHa]

OK, I've got everything sealed down to the cut off between the tank and line. It is still resisting me.

[jdome]

Do not use standard box wrenches or worse yet adjustable  wrenches on braass fittings, especially 100 year old fittings. You are likely distorting the fitting.  Buy a set of "flare fitting wrenches " These are special 6 point box wrench with one point cut open enough to slide past the diameter of the tubing and grab 5 of the corners of the nut. They distribute the force on 5 corners instead of just 2 opposite corners like an open end wrench which will deform the soft brass or copper nut and flare face. 

Farrell and actual flared tube ends didn't  come into common use until the teens. Your originals are probably soldered on flare pieces like plumbing couplers/joints. If your tubing ends are tool flared on a 1911 car I suspect they are replacement. 

[hook]

The problem with 100 year old Brass fittings is that the brass gets hard with age and cracks. The pressure in a fuel system is not great but may still cause problems. However I would suggest not using the old brass fittings on brake systems.

[AHa]

Yes, what I'm dealing with is a solder on flare joint. I have been using open end wrenches. I'll look for the flare wrenches.

[dibarlaw]

For my 1925 Buick I had to make my own ("Double compression, Dole fitting, Tube nut".)

These were the descriptors I found for my fuel line fitting from the vacuum tank shut off to my carb. The parts book refered to them as nipples.

I had spent hours online searching for them. A while ago I had gotten some from Fastenal for 1/4" tube but they no longer had them for 5/16" tube.  O'Reilly auto parts supposidly stocks them. (free overnight store delivery) But to get them delivered to me was turning into a fiasco. I ordered 10 (@$3.29 each) shipping was calculating for 10 individual orders, the cost was going to be over $50.00 just for shipping! The closest parts store to me was over an hour away.

[jdome]

above are what the fitting wrenches look like.   The soldered fittings are usually more substantial than flared ends. Make sure the mating faces are not damaged or cracked.  you may have to machine or sand paper the faces so they seal better. 

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[AHa]

I wanted to give an update to this problem in the hope that I might help the next guy who runs into this problem. What shoulda been very obvious wasn't. It wasn't the flare connection that was leaking; it was the solder joint next to it. It took me a while to find a 7/8 flare wrench. I'm kinda stupid as I still prefer to buy from local suppliers. To be fair, however, several suppliers said that had the wrench, both online and in store, only it turned out they didn't. When I finally found one at Ace, one village over, I figured out my solder joint didn't take. Several more attempts didn't take as well, and about the time I was ready to give up, I carefully set all my pieces up and set a chair in front of my work and got success. For some reason I decided to try and blow through the line and that's when I discovered the solder had completely blocked the line. A 1/4" drill bit cut out the excess solder and I blew the line out, installed it, and turned on the gas with no leaks. 

[DFeeney]

I would avoid any kind of putty.  In the long run it will come back and bite you and perhaps burn the shop down.

[AHa]

Talking about burning the shop down, a friend in Canada always left the radio playing in his shop until one day it shorted out and burned the shop down with his car inside. The experts do recommend a little thread sealer smeared on the flares if you can't get them to seal. The 410a refrigerant is notoriously hard to seal up with flared fittings but that's a whole different kind of gas.

[Frank DuVal]

The sealant for flare refrigerant fittings is Blue Nylog. (Or red Nylog). The refrigerant is not a solvent for these products. I've never used sealant on other flare fittings. There are copper sealing washers you can use on the flares. Parker makes them.

 

Glad AHa had the AHa moment and fixed the issue!👍

[WPVT]

There was one of those fittings on a Chevy 216 that I used to own. It was on a small diameter oil line that passed through the water jacket into the block. I saw a small water leak and tightened the fitting, inadvertently breaking the solder seal. 

In this instance, the fitting had to be positioned onto the line (it was not at the end of a line), screwed into the block, and then soldered. 

I replaced the head gasket many times, trying to eliminate oil in the cooling water before I figured out the actual problem, that tiny soldered fitting.