Vintage Garden Syringe Sprayers    

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SOME THOUGHTS ON REPLACING PACKING

 This is a fairly straightforward process and it doesn’t matter too much how it is done as long as it works. I have tried several methods and still not sure I have found the best approach. This represents my thinking so far.

Material

1. Cotton string. The softer ones seems slightly better, but it doesn’t seem to make a big difference.

2. Medium cotton thread which is freely available.  

Stage 1


Remove old packing. Hold the plunger rod in a vice or similar so both hands are free.   


Stage 2


Cut a suitable length pf string about 6 ft. I think the process works best if the string is kept dry, but this is open to more investigation. Start winding on from the far end of the piston. Wind on carefully avoiding crossing over. If there are groves in the reel follow these.  

 Stage 3

At the end of the reel start winding back this time with the string going in the groves created by the previous layer. Then add a third layer using the same approach, so you have three layers. This is normally correct for most pistons. Cut the string so you have a small end.

 Stage 4

Tie a piece of the cotton thread onto the end if the string . Then wind on the cotton thread between the string of the last layer. Continue winding on the thread until the level is fairly even and just above the edge of the reel. Cut the thread and any excess of string. Tuck in the thread end. Wet the piston and insert the plunger into the barrel and push/pull it a few times. It should be a reasonably tight fit. Remove the plunger and check the piston. It should show signs that it has been in even contact with the sides of the barrel.

Stage 5

Try the syringe. Normally, they will fill, but there may be leakage behind the piston, when spraying. This will either come out of the air vent or along the plunger . If there is a drip guard it will run down the barrel. If there are problems add a few more layers of cotton thread and try again. If the leakage is along the plunger rod and a stuffing box is fitted then check this as well as adding more thread. Some leakage is expected from this type of piston, I have been greasing the piston with petroleum jelly, as suggested by a professional gardener who used the sprayers in the 1950’s, but not sure how correct this is.