Hi. I have a bypass filter setup with several different pipe fittings. There are two brass pipe fittings that I would like to disconnect and attach somewhere else. They were expensive and hard to get. The problem is, when I purchased them, they came epoxied together. Epoxy is plastic right? My question is, does anyone think I can't loosen the adhesion with a big wrench and a lot of force? If I do this would they be reusable? I appreciate anyone's advice.
Strange question about epoxy and pipe fittings
- Thread starter mjo
- Start date
- Status
if it is a real epoxy, it's not plastic. depending on the particular epoxy, you might get them loose, but i seriously doubt you could reuse them unless you can clean them up. any epoxy would have to be removed, and that may take grinding.
Give it your best shot with muscle power, and if that doesn't work maybe try some heat. Most good epoxy such as J-B Weld is rated up to about 500 degrees Fahrenheit continuous, or 600 degrees for 10 minutes. If you use a torch to heat the joint real hot, you should have an easier time separating them. However, you better take precautions not to set your oil or vehicle on fire.
Can the joint be removed from the car? Are hoses involved? Maybe you could cut the hoses, and bring the joint to your bench for "surgery". Use a six point wrench or a quality flare wrench to keep from rounding off the corners.
If the epoxy is only on the threads, and not slathered all over the exterior of the joint, then muscle power might be enough. Usually with pipe thread fittings, very little pipe joint compound actually remains in the threaded area after assembly. After you separate the fittings you can clean them up with a tap and die. Or a wire brush may be sufficient.
By the way, when assembling pipe thread joints (like NPT or BSPT threads), the recommended procedure is apply joint compound (e.g. Permatex #14), and assemble finger tight. Then after you can't use your fingers any more, switch to a wrench and follow the spec for "turns past finger tight". That is, the additional number of turns using a wrench.
For your average 1/8 NPT and 1/4 NPT pipe threads, the T.P.F.T. spec is 2 to 3 turns past finger tight. Generally this means that at least 4 to 6 threads are engaged. If you go too much past 6 engaged threads, then you are getting into the neighborhood of overtightening and possibly stripping the joint.
Oh, and some folks use teflon tape instead of joint compound, but I'm not personally a big fan of tape on automotive pipe joints.
Can the joint be removed from the car? Are hoses involved? Maybe you could cut the hoses, and bring the joint to your bench for "surgery". Use a six point wrench or a quality flare wrench to keep from rounding off the corners.
If the epoxy is only on the threads, and not slathered all over the exterior of the joint, then muscle power might be enough. Usually with pipe thread fittings, very little pipe joint compound actually remains in the threaded area after assembly. After you separate the fittings you can clean them up with a tap and die. Or a wire brush may be sufficient.
By the way, when assembling pipe thread joints (like NPT or BSPT threads), the recommended procedure is apply joint compound (e.g. Permatex #14), and assemble finger tight. Then after you can't use your fingers any more, switch to a wrench and follow the spec for "turns past finger tight". That is, the additional number of turns using a wrench.
For your average 1/8 NPT and 1/4 NPT pipe threads, the T.P.F.T. spec is 2 to 3 turns past finger tight. Generally this means that at least 4 to 6 threads are engaged. If you go too much past 6 engaged threads, then you are getting into the neighborhood of overtightening and possibly stripping the joint.
Oh, and some folks use teflon tape instead of joint compound, but I'm not personally a big fan of tape on automotive pipe joints.
Thanks everyone for the advice. I didn't know about the T.P.F.T. spec, this will help in the future. I'm able to take the part off of the vehicle and clean the oil off of it so burning won't be a problem. BTW, If I heat the epoxy to a high temperature will it turn into a liquid and spread deeper into the fitting or will it shrivel up and burn/ evaporate/ etc?
I'd try heat [propane or MAP], before trying to unscrew them. Brass is soft. You'll smell and see the epoxy when it breaks down.
You're welcome, mjo. Glad to be of help.
When you heat the epoxy it will initially soften and become pliable long before it burns up. I speak from experience of using a torch to remove electronic components from scrapped epoxy circuit boards. Heat will make the epoxy sag like a limp . . . whatever.
T.P.F.T ("turns past finger tight") specs are interesting because normally one would find a torque spec for threaded fasteners. But in the case of pipe threads you have the additional variable of a thread sealant which could have a wide range of coefficient of friction, depending on the sealant. So it is more reliable to use T.P.F.T than torque when dealing with pipe fittings. If you are interested in more information, Maryland Metrics has this assembly guide (pdf) which you can download, if you think that you might find it useful. They refer to the spec as "Turns From Finger Tight" T.F.F.T. The pdf includes tables with values for different types and sizes of fittings.
When it comes to a high performance thread sealant for automotive applications, I highly recommend "Permatex High Temperature Thread Sealant" (part number 59214). This is NOT an "instant put in immediate service" type sealant like Permatex #14. On the contrary, "Permatex High Temperature Thread Sealant" requires several hours of curing time before putting the joint into service, and will actually continue to cure for 72 hours. It provides a solid, heat resistant, vibration proof seal, but it can easily be disassembled when need be.
Permatex lists the following attributes for "High Temperature Thread Sealant":
Many years ago, there was one main choice for automotive threads sealants, good old Permatex #2. You might remember it as that black goo which required alcohol to clean up. We sure do have a lot more choices now, with better chemistry. Permatex "High Temperature Thread Sealant" gets my vote as the current "top dog".
[and no, I'm not associated in any way with Permatex]
When you heat the epoxy it will initially soften and become pliable long before it burns up. I speak from experience of using a torch to remove electronic components from scrapped epoxy circuit boards. Heat will make the epoxy sag like a limp . . . whatever.
T.P.F.T ("turns past finger tight") specs are interesting because normally one would find a torque spec for threaded fasteners. But in the case of pipe threads you have the additional variable of a thread sealant which could have a wide range of coefficient of friction, depending on the sealant. So it is more reliable to use T.P.F.T than torque when dealing with pipe fittings. If you are interested in more information, Maryland Metrics has this assembly guide (pdf) which you can download, if you think that you might find it useful. They refer to the spec as "Turns From Finger Tight" T.F.F.T. The pdf includes tables with values for different types and sizes of fittings.
When it comes to a high performance thread sealant for automotive applications, I highly recommend "Permatex High Temperature Thread Sealant" (part number 59214). This is NOT an "instant put in immediate service" type sealant like Permatex #14. On the contrary, "Permatex High Temperature Thread Sealant" requires several hours of curing time before putting the joint into service, and will actually continue to cure for 72 hours. It provides a solid, heat resistant, vibration proof seal, but it can easily be disassembled when need be.
Permatex lists the following attributes for "High Temperature Thread Sealant":
- Prevents leakage from vibration, temperature cycling, and extreme pressures.
- Protects against rust, corrosion, and galling of threads.
- Parts repositionable after application.
Many years ago, there was one main choice for automotive threads sealants, good old Permatex #2. You might remember it as that black goo which required alcohol to clean up. We sure do have a lot more choices now, with better chemistry. Permatex "High Temperature Thread Sealant" gets my vote as the current "top dog".
[and no, I'm not associated in any way with Permatex]
Ive been a pipefitter for over 23 years and have used all types of thread lubricants/sealants.My favorites are Leak Loc and Expando.Leak Loc is a paste type thread sealant which requires no curing time to apply pressure and when fully cured is similar to Loc Tite red or blue.Expando is a powder that you add water to make it a paste.It is similar to JB Weld when fully cured; bullet proof and can be drilled.It can be used on stripped threads.It is also "oxygen" safe.I only use it as a last resort or when I dont need to take a joint or fitting apart.
- Status