What's new
What's new

Large leather hydraulic cup seal still rock hard after 2 day oil soak, too hard to install

tomjelly

Stainless
Joined
Aug 26, 2007
Location
GA
Ordered a new seal and soaked it in the same aw32 hydraulic oil that will be in the cylinder for the last 2 days and it's still hard as a rock. The cylinder opening has a generous starting taper but no way this is going in without what seems like would be the kind of force that would damage it. I have a piston ring compressor that size but no way would it work. The bad one that came out was nice and flexible. Am I just being too impatient needing a longer soak or what? Seal is 1/4," thick 6" od with around 1" flange...
 
IMO 1/4" leathers going to be hard to bend to a solid right angle, even if it was super supple. How much of a radius did the old one have? I assume there are some big washers on either side. How much smaller are they than the cylinder ID? Are you sure the old one wasn't skived (tapered) around the perimeter?

Leather hides always have a variety of thickness's and densities across the surface. The density is effected with the tanning process and they strive for uniformity, but as it's the whole hide getting treated and cows are shaped funny (materially speaking), hard spots can get harder and soft spots can get softer. It's more like lumber than metal. The number of voids and defects in the product directly correlates to it's price and how high a yield the manufacturer was trying to get out of their hides. Your piece could just be the hard piece that slipped by.
 
Temp might explain it, my shop is 50 f. The seal is factory formed ready to install but came dry, with a stiffness and hardness similar to wood. As I understand they are made wet over a wooden male/female form and allowed to dry in the mold. I'll try the hot oil treatment next.
 
Temp might explain it, my shop is 50 f. The seal is factory formed ready to install but came dry, with a stiffness and hardness similar to wood. As I understand they are made wet over a wooden male/female form and allowed to dry in the mold. I'll try the hot oil treatment next.

Don't make me send flowers to the burn unit!
[Like, be careful, keep an appropriate extinguisher at hand]
 
I would use leather oil not a inorganic oil. Like shoe oil. Possibly a double boiler, outside. I do not know the flash point of neats foot oil.
Bill D

edit: Flash Point: 316°C / 600°F
 
I'm going to try putting the seal in aw32 in a pan on an electric pancake griddle at 150 for a few hours, then a hose clamp to see if I can get any flexibility. Luckily just got a new cast iron griddle so I can use the old worn out Teflon one for the shop. If that doesn't work I'll check &see what the vendor uses after Christmas.
 
I'm going to try putting the seal in aw32 in a pan on an electric pancake griddle at 150 for a few hours, then a hose clamp to see if I can get any flexibility. Luckily just got a new cast iron griddle so I can use the old worn out Teflon one for the shop. If that doesn't work I'll check &see what the vendor uses after Christmas.
If it was originally formed using water, why not soak it in water to soften and install it?
 
If it was originally formed using water, why not soak it in water to soften and install it?
Because you don't want a "water wet" sponge going into your steel hydraulic cylinder?

I'd stick with using the same oil that will be in the system, and if using a pan on a griddle you may want to put a second, larger, pan or similar thing over it to prevent the wind and cold from chilling it to quickly (presuming you're outdoors, which you should be).
 
Because you don't want a "water wet" sponge going into your steel hydraulic cylinder?

I'd stick with using the same oil that will be in the system, and if using a pan on a griddle you may want to put a second, larger, pan or similar thing over it to prevent the wind and cold from chilling it to quickly (presuming you're outdoors, which you should be).
Good point, but you could soak it, then insert just the very end, and let it dry out before final assembly.
 
I think the OP would like it to be pliable in use so it can best do its job. Just reforming it to "rigidly" sit in the cylinder won't help it seal.
Hmmmm....I was thinking that once completely installed, the hydraulic oil would soak it and make it soft-but you're probably right-if the oil isn't soaking in while the leather is open on all sides, it probably wouldn't do so while the seal is installed.
 
Don't make me send flowers to the burn unit!
[Like, be careful, keep an appropriate extinguisher at hand]
I wonder if an immersion cooker (sous vide machine) would work well for this? Obviously it'd be retired from kitchen use, but it seems to be the perfect solution.
 








 
Back
Top