The Ford Barn

rfitzpatrick · 04-02-2020, 10:36 AM

How would I check carburetor for cracks -- magnaflux/dye-check?
Thanks

Joe K · 04-02-2020, 10:50 AM

Usually just blasting clean will make a crack visible. If not you can dip the carburetor body in paint thinner (mineral spirits) wipe it off quick and find any cracks.

Magnaflux would be the expensive way. Better for homogenious ferrous materials not so much for cast iron.

And dye-check would be best after blasting anyway - think Thinner that glows under UV light.

Depending on where the crack is, one can seal it on the inside with Glyptol - which is a coating used by electricians on motor windings, but famously used on race-car transmission cases to keep grit from the metal casting out of the lubricating oil and gears. Alcohol based, Glyptol, once dry can't really be cut by much of anything, including gasoline. You will struggle to remove Glyptol with paint stripper (MEK primarily)

Hope this helps.

Joe K

redmodelt · 04-02-2020, 04:46 PM

What brand/kind of carb and where do you think the is crack?

old31 · 04-02-2020, 05:08 PM

Joe, thats really interesting on what you said about the cracks and Glyptol.

I would call that "crackalicios".

rfitzpatrick · 04-03-2020, 06:19 AM

What brand/kind of carb and where do you think the is crack?

It's a Zenith 2, not that I know it's cracked -- just wanted to know how to inspect for any.
Thanks

redmodelt · 04-03-2020, 07:41 PM

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Low cost way; clean, install parts, fill with gas to proper level and let sit. If you leave the top off you can get gas creep up the sides so put the top on too. Gasket set would cost a lot less then the dyes etc for doing one carb. Of the few dozen Zenith's I have taken apart, don't recall any cracks. Stripped/pulled threads; yes. Broken mounting flanges; yes. Bad seat for the inlet pipe; yes. Pitting where the float valve mounts; yes. The only place that in my OP might be cracked would be where the fuel inlet screws into. Heck you can heat to orange in localized areas to get stuck parts out and drop in bucket of cold water and still not crack them.

(Well so far I haven't)
Or clean and look for rust trails.

Jack Shaft · 04-03-2020, 08:22 PM

Dye penetrant kits are about 80 bucks on amazon...more that adequate for checking your carb,with a bunch left over

04-02-2020, 10:36 AM	#1
rfitzpatrick Senior Member Join Date: May 2018 Location: Coral Springs, Florida Posts: 551	Hair-Line Crack How would I check carburetor for cracks -- magnaflux/dye-check? Thanks

04-02-2020, 10:50 AM	#2
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Hair-Line Crack Usually just blasting clean will make a crack visible. If not you can dip the carburetor body in paint thinner (mineral spirits) wipe it off quick and find any cracks. Magnaflux would be the expensive way. Better for homogenious ferrous materials not so much for cast iron. And dye-check would be best after blasting anyway - think Thinner that glows under UV light. Depending on where the crack is, one can seal it on the inside with Glyptol - which is a coating used by electricians on motor windings, but famously used on race-car transmission cases to keep grit from the metal casting out of the lubricating oil and gears. Alcohol based, Glyptol, once dry can't really be cut by much of anything, including gasoline. You will struggle to remove Glyptol with paint stripper (MEK primarily) Hope this helps. Joe K __________________ Shudda kept the horse.

04-02-2020, 04:46 PM	#3
redmodelt Senior Member Join Date: May 2010 Location: Portland OR Posts: 6,340	Re: Hair-Line Crack What brand/kind of carb and where do you think the is crack? __________________ I know the voices aren't real but damn they have some good ideas!

04-02-2020, 05:08 PM	#4
old31 Senior Member Join Date: Jan 2016 Posts: 2,093	Re: Hair-Line Crack Joe, thats really interesting on what you said about the cracks and Glyptol. I would call that "crackalicios".

04-03-2020, 06:19 AM	#5
rfitzpatrick Senior Member Join Date: May 2018 Location: Coral Springs, Florida Posts: 551	Re: Hair-Line Crack What brand/kind of carb and where do you think the is crack? It's a Zenith 2, not that I know it's cracked -- just wanted to know how to inspect for any. Thanks

04-03-2020, 07:41 PM	#6
redmodelt Senior Member Join Date: May 2010 Location: Portland OR Posts: 6,340	Re: Hair-Line Crack Sponsored Links (Register now to hide all advertisements) Low cost way; clean, install parts, fill with gas to proper level and let sit. If you leave the top off you can get gas creep up the sides so put the top on too. Gasket set would cost a lot less then the dyes etc for doing one carb. Of the few dozen Zenith's I have taken apart, don't recall any cracks. Stripped/pulled threads; yes. Broken mounting flanges; yes. Bad seat for the inlet pipe; yes. Pitting where the float valve mounts; yes. The only place that in my OP might be cracked would be where the fuel inlet screws into. Heck you can heat to orange in localized areas to get stuck parts out and drop in bucket of cold water and still not crack them. (Well so far I haven't) Or clean and look for rust trails. __________________ I know the voices aren't real but damn they have some good ideas!

04-03-2020, 08:22 PM	#7
Jack Shaft BANNED Join Date: Dec 2019 Posts: 1,196	Re: Hair-Line Crack Dye penetrant kits are about 80 bucks on amazon...more that adequate for checking your carb,with a bunch left over