Looking for a machinist for a small project

[sfcairborne]

Looking for a machinist for a small project
Would like to have someone machine me a steel lube plunger plug for the rcbs lube a matic, gen 1. The **** o rings that go around the plunger plug to seal the inside tube keep ripping and I’m tired of replacing them and loosing my lube to the top of the plunger. Anyone up for the task. I’ll send my lube sizer clean of course so the correct inside measurement of the tube.

Thank You

[country gent]

What material is the current plunger made from? Steel brass or aluminum should work for this part. Another thing to check is how rough the tube is. this can also affect o-ring life. Another would be to check for sharp edges, these can cut the O-rings when starting the plunger or when they pass over them. A few things to check before going to making new parts.

[sfcairborne]

The current plunger I believe is made from steel. Has the two o ring groves. My lube of choice is Randy Rats TAC-1, it's a little hard, could use a heater I think but I don't have one at the moment. What is happening is the lube is pushing the O rings out of the designated groves, which allows the lube to flow over the top of the plug. I have been to my local hardware store and purchased a ton of different size mostly smaller in diameter, o rings to try and help them stay in the groves, but they still seem to come out. Hence the problem. The inside of the lube tube is smooth and free of burrs.

[kir_kenix]

Before you make a new part, maybe try better o-rings. I think I'm using viton instead of neoprene. They last alot longer...maybe 2-3 cents more for each one. Auto parts store will have them in a variety of sizes.

[country gent]

A hard lube ran cold may require a complete redesign on the plunger to possibly work. Some thing to consider O-Rings in hydraulic cylinders stand up to 3000+ psi routinely. I his could easily be passed with the screw thread and a cold hard lube. A little heat from a blow drier warming the tube occasionally or a heat lamp/trouble lamp would warm the machine. nothing fancy or excessive just space the lamp far enough form the tube to maintain temp when on. Another would be the element from a curling iron in an aluminum plate under the lubesizer.
The new piston could be made as a 2 piece assembly. a nylon cup with thin lop fastened to a steel plug very closely fit to the tube, by close I mean .002 - .003 clearance between tube and plunger. 3 o rings to seal back side. In use the nylon cups thin lip would expand under the pressure as a primary seal that is set by lube pressure. The close fitted plug would be almost a seal limiting what could push past it and limiting "pressure" on the o rings. The 3 o rings would then be the final seal and catch all. This type set up can handle a lot of pressure with little to no blow by, but is also used where there is lubrication.
While the above style piston would seal the higher pressures of cold hard lubes, the added pressure generated by the higher pressures may cause the fine threads in the drive rod to strip and or wear excessively. Here a new drive rod and cap would need to be made. A longer threaded rod from harder material. A new cap from better materials with a stem and longer thread to take the pressure.
If there is a plug sealing the tube the added pressures may then blow past there also.

This could end up being a complete redesign rebuild of the lube sizer and its parts. The trouble light with the appropriate wattage bulb spaced away may do what you want. The old soup vending machines that sold hot soup in the can were heated with a 100 watt bulb or so. The simple cheap trouble light should do the job

[samari46]

I've used viton o rings when doing an mechanical seal or seals for fuel oil pumps. Viton can handle petroleum products way better that the neophrene o rings can. I've seen neophrene o rings swell up from coming into petroleum products and they are not as abrasion resistant as the viton rings. So I would first make sure the piston on the lubricator is free of nicks and burrs. And the same for the area where the piston is going up and down. And when you insert the viton rings a good silicone grease on the o rings is also suggested as well. And while it may pie in the sky the bore for the piston is should be as smooth as possible. And while it may sound crazy those o rings in your faucetts that have o rings in them, most say lubricate with silicone grease when doing the installation.Frank

[retread]

A hard lube ran cold may require a complete redesign on the plunger to possibly work. Some thing to consider O-Rings in hydraulic cylinders stand up to 3000+ psi routinely. I his could easily be passed with the screw thread and a cold hard lube. A little heat from a blow drier warming the tube occasionally or a heat lamp/trouble lamp would warm the machine. nothing fancy or excessive just space the lamp far enough form the tube to maintain temp when on. Another would be the element from a curling iron in an aluminum plate under the lubesizer.
The new piston could be made as a 2 piece assembly. a nylon cup with thin lop fastened to a steel plug very closely fit to the tube, by close I mean .002 - .003 clearance between tube and plunger. 3 o rings to seal back side. In use the nylon cups thin lip would expand under the pressure as a primary seal that is set by lube pressure. The close fitted plug would be almost a seal limiting what could push past it and limiting "pressure" on the o rings. The 3 o rings would then be the final seal and catch all. This type set up can handle a lot of pressure with little to no blow by, but is also used where there is lubrication.
While the above style piston would seal the higher pressures of cold hard lubes, the added pressure generated by the higher pressures may cause the fine threads in the drive rod to strip and or wear excessively. Here a new drive rod and cap would need to be made. A longer threaded rod from harder material. A new cap from better materials with a stem and longer thread to take the pressure.
If there is a plug sealing the tube the added pressures may then blow past there also.

This could end up being a complete redesign rebuild of the lube sizer and its parts. The trouble light with the appropriate wattage bulb spaced away may do what you want. The old soup vending machines that sold hot soup in the can were heated with a 100 watt bulb or so. The simple cheap trouble light should do the job

I run randyrats Tac-1 in my 450. I do not use a heater but I have not run it in real cold weather as I am on the coast and the temps are moderate. I would think Oklahoma would be warmer that here. Silicone grease on viton o-rings sounds like a good place to start.

[slughammer]

Whatever type of o-ring you use, you should lubricate it well when you install the piston into the reservoir.

On my Lubamatic, 450, and Star I use petroleum jelly (vaseline) all over the o-rings/seals and into the mouth of the reservoir. This helps the o-ring slide in the reservoir instead of sticking to the sides. Makes installation much easier.

Also, use the correct size o-rings. Using a smaller one just stretches it thinner and gives less compression to the reservoir wall.

[Conditor22]

This is RCBS we're talking about. Call them. They may recommend O rings, a new plunger or just send you one (or both).

[JonB_in_Glencoe]

I wonder how close in diameter the old style Lyman pressure nut with brass sleeve is to the internal diameter of your RCBS LAM I lube reservoir?

No Orings to wear or get pinched/cut on the old style Lyman. The Brass sleeve has a notched split, so it can expand under pressure, while they are known to leak a tiny bit under high pressure and especially if Lube is heated up too much, it should work great for you application.

While the Pressure Screw's threads are different from RCBS and Lyman, that part would be easily enough made/modified, if the Lyman Pressure screw wouldn't work as is.

[David2011]

Tulsa is plenty cold in the winter.

I would be concerned that smaller O-rings would displace more easily than larger ones. A snug fit against the piston and the wall of the tube will seal best.

A heater is easy and cheap to make. Mine is a 6"x12" piece of aluminum upon which I set a $3.00 Goodwill clothes iron that I set on low. I adjust the temperature by varying the distance between the sizer and the iron. Light steel would work about as well as the aluminum. I use TAC-1 and heat it a little except in the warmest months. My reloading room is in a detached workshop but heavily insulated so it's never as cold or as hot as the ambient temperature.

[EDG]

I have 4 Lyman and 2 RCBS lube sizers.
I bought the first RCBS generation 1 lube sizer in 1975.
I have never had a torn O ring. You are doing something wrong to have O ring problems.
I once worked at a pressure vessel company that tested O rings to 9000 psi. i have also worked in a semiconductor equipment company that produced ultra high vacuum equipment. The vacuum produced went down to 1X10-9. Torr. You should review how you are using your tools.

[sfcairborne]

Thanks for the replies. Going to get a lube heater and see if that helps. I've had the lube for quite a while now, but it has been stored in a ziplock and inside the house under a cabnet, it may have dried out a little bit. I've coated the new rings with Vaseline to see if that will keep them from sticking to the side wall and being pulled up. Been trying to reach RCBS but have not been able to reach them as of yet, in order to get some O rings from them. Too me this lube is hard, and I do heat the main tube up with a heat gun to get it flowing, without it, it becomes to hard to move.