Who makes new carburetor floats to replace old brass cracked floats?

[mikewest]

I would like to buy a new float for a glass bowled Stromberg carburetor 1910s era??  Mike West

[Marty Roth]

If you still have the old one, why not coat it with shellac, 

or make a new one out of cork from a fishing supply place?

I've done that and it works fine

[cudaman]

I'm not sure that shellac will hold up to modern gasolines with alcohol added.  I use Pactra clear "Hot Fuel Proof" Dope made for model airplanes.  It's designed to stand up to the methanol and nitromethane model airplane fuels.

 

Restoration Supply sells a modern material that you can carve to match the shape of your old float.  It is a closed cell plastic, so it doesn't need to be sealed.

[Str8-8-Dave]

For sure, if you are going to coat a float with fuel proof coating, don't use shellac, use what cudaman suggested, Pactra hot fuel proof dope which is fuel proof in nitromethane, a much harder test than fossil fuels dispensed at the gas pump even if it's 85% ethanol (don't use that either).  I use SIG hot fuel proof butyrate dope, also commonly available at hobby stores.  

 

As for coating a brass float- they were lead alloy soldered.  If you have a float with metal fatigue cracks, I'm not sure hot fuel proof dope is adequate.  Firs you would have to make sure there is no fuel trapped inside the float adding weight, second, a coating of dope may or may not adhere well on brass, it's intended for use on wood products, jap tissue and silk.

 

If you are going to fabricate a float from cork, you have to make sure it is virgin natural cork which is difficult to find.  Most cork you find today is recycled and is ground up powder that is glued, it has nowhere near the buoyancy of virgin cork used in the old days when it was commonly available.  Today, a better choice if you are going to fabricate your own is block balsa which has a slightly better buoyancy that even pure cork, can absolutely be effectively sealed with Pactra or SIG hot fuel proof dope and is easy to work with.  I'm leery of modern nitrophyl plastic floats because I had a couple of those saturate with gasoline and sink, in one case causing a very expensive fire.  I made a float to replace the original cork item for my 1931 Buick's Marvel, model 10-795.  It went in 3 years ago and still floats like a champ. 

 

An original Marvel cork float with its brass arm and float valve.  I had flooding issues with this float which probably absorbed some fuel over its 90-year lifespan.

I also found under the magnification of jeweler's goggles that there was some fine chalky residue coating on the float valve which I polished off with 2000 grit

wet/dry sandpaper, then polished with Happich Simichrome paste chrome polish.

 

The new float was copied exactly from the original, cut from 1-inch-thick balsa block.

 

The float was coated with SIG butyrate hot fuel proof dope before and after assembly to the float arm.

 

 

Finally- here it is on the job in the Marvel 10-795 carburetor.

Edited July 10, 2022 by Str8-8-Dave
Arrange pictures, captions (see edit history)

[Marty Roth]

7 hours ago, cudaman said:

I'm not sure that shellac will hold up to modern gasolines with alcohol added.  I use Pactra clear "Hot Fuel Proof" Dope made for model airplanes.  It's designed to stand up to the methanol and nitromethane model airplane fuels.

 

Restoration Supply sells a modern material that you can carve to match the shape of your old float.  It is a closed cell plastic, so it doesn't need to be sealed.

 

1 hour ago, Str8-8-Dave said:

For sure, if you are going to coat a float with fuel proof coating, don't use shellac, use what cudaman suggested, Pactra hot fuel proof dope which is fuel proof in nitromethane, a much harder test than fossil fuels dispensed at the gas pump even if it's 85% ethanol (don't use that either).  I use SIG hot fuel proof butyrate dope, also commonly available at hobby stores.  

 

As for coating a brass float- they were lead alloy soldered.  If you have a float with metal fatigue cracks, I'm not sure hot fuel proof dope is adequate.  Firs you would have to make sure there is no fuel trapped inside the float adding weight, second, a coating of dope may or may not adhere well on brass, it's intended for use on wood products, jap tissue and silk.

 

If you are going to fabricate a float from cork, you have to make sure it is virgin natural cork which is difficult to find.  Most cork you find today is recycled and is ground up powder that is glued, it has nowhere near the buoyancy of virgin cork used in the old days when it was commonly available.  Today, a better choice if you are going to fabricate your own is block balsa which has a slightly better buoyancy that even pure cork, can absolutely be effectively sealed with Pactra or SIG hot fuel proof dope and is easy to work with.  I'm leery of modern nitrophyl plastic floats because I had a couple of those saturate with gasoline and sink, in one case causing a very expensive fire.  I made a float to replace the original cork item for my 1931 Buick's Marvel, model 10-795.  It went in 3 years ago and still floats like a champ. 

 

An original Marvel cork float with its brass arm and float valve.  I had flooding issues with this float which probably absorbed some fuel over its 90-year lifespan.

I also found under the magnification of jeweler's goggles that there was some fine chalky residue coating on the float valve which I polished off with 2000 grit

wet/dry sandpaper, then polished with Happich Simichrome paste chrome polish.

 

 

The new float was copied exactly from the original, cut from 1-inch-thick balsa block.

 

 

The float was coated with SIG butyrate hot fuel proof dope before and after assembly to the float arm.

 

 

 

 

Finally- here it is on the job in the Marvel 10-795 carburetor.

 

Dave and cudaman,

 

Thanks Guys,

I continue to learn

[Layden B]

Unless your brass float is smashed or otherwise destroyed solder it up.

The small amount of weight added will not affect the action of the float.

[Terry Harper]

Hello Mike,

 

Is the float missing or damaged (bent, dented, smushed) beyond repair or plunging to the bottom like a rock?

[mikewest]

No its intact but has stress cracks. Its been soldiered up one. I might try again . 

[Terry Harper]

1 minute ago, mikewest said:

No its intact but has stress cracks. Its been soldiered up one. I might try again . 

 

Hopefully it doesn't look this ugly.... but it still works!

 

 

[mikewest]

No Mine is better looking , but taking on fuel. 

[Bloo]

The biggest problem is that the pressure that develops inside from heat will blow a hole in your solder as you attempt to repair.

 

Most floats have a tiny hole somewhere independent of the seams with a small dot of solder over it. Open that hole while you do your repair. Then, solder it back shut last. You will need to do something to reverse the flow of air while you solder that little hole shut. Dunking the opposite end of the float, the end away from the hole, in ice water as you are taking the soldering heat away might work. Electronic "freeze mist" might also work, but you would probably need a second person to spray it at the far side. You don't want to overdo the cooling and get the air flowing the other way.

 

To test a repaired float, sink it in hot water and look for bubbles.

 

[Jubilee]

Don’t forget Seal All for float coating and leak repair

[Stude Light]

I just made one for a 1909 Reo out of the nitrophyl block you can buy from Restoration Supply or other outlets. It is a simple cylindrical design so was very easy to make on a lathe. The nitrophyl is easy to shape with some sandpaper for a more intricate design. If you have to add “brackets” you can glue them on with gas proof adhesive or even thread into it (go as deep as you can into the material).

 

I even made a hybrid one out of cork and nitrophyl once because I only had just enough of each material to make half a float at the time.

[Mark Shaw]

• Glue 3-4 wine corks together for a large enough float.
• Use a graindr or sander to shape cork to fit and move freely in the float bowl.
• Attach the float needle assy.
• Coat the finished cork/needle float with Krazy Glue to seal and protect it from ethanol/gasoline.

 

Edited July 12, 2022 by Mark Shaw (see edit history)

[Larry Schramm]

I have done exactly as Mark describes and it has worked well.  No issues. 

[Terry Harper]

Those are all good repairs. However, I think Mike's issue is that its a glass bowl carb so the float is visible. As such he probably wants to retain a brass float. I think his best bet is soldering up the cracks as suggested earlier.

Good tip on having to allow it to vent when soldering!