In a bygone era of cheap solvent, transfer machinery and Per Combo filters and cooker stills, a drip was generally no big deal. Fortunately, for our industry, (some might argue this point) the costs of solvent coupled with environmental regulations have markedly sharpened our maintenance and housekeeping practices. With this in mind, I’m dedicating the next few articles to the selection of/and techniques involved with maintaining and replacing that ubiquitous device, the “lowly gasket.”
Beginning with the dry cleaning machine, we find what are probably the four most recognizable gaskets you deal with on a daily basis: The loading door, button trap door, lint trap door (on many dry cleaning machines the lint and button trap are enclosed in the same housing) and still door. Even the most unaware operator cannot long ignore a solvent leak at the loading door. However, you’d be surprised at how few operators take the time to go behind the machine with a good flashlight and observe the still door during heavy distillation. In many cases a grungy still waste container sits under the still door and the surrounding area is often caked with old still residue. Because of this, even large leaks can go undetected if the timing and lighting are not opportune (the price of solvent being what it is, these liquid type leaks cost you big time). Lint and button trap leaks are usually of the vapor variety and harder to locate. Now that you are aware of the problem areas let’s explore them one by one and see how you can isolate the leaking area and stop the fluid loss.
Loading Door
When you notice a solvent leak at the loading door it will almost always appear that the bottom area of the door gasket is at fault. That’s because gravity being what it is, the liquid solvent leaking past the gasket rolls down the surface of the door and drips off of the bottom center. When you see a leak like this you need to take action at the end of the load that’s currently being processed. Don’t despair, the chances are good a simple fix will get you back on track.
When the load is finished and the door opened, look at the surface of the gasket. Generally, there will be a slight groove in the gasket caused by the pressure against the raised portion on the dry cleaning machine that the door seals against. Often, lint accumulates in this groove and prevents the proper mating of the gasket against the machine front. It is a good idea to routinely clean this groove keeping it free from lint. On newer machines the rubber of this gasket is a solid robust type and can be cleaned easily with a small wire brush (if the gasket is a type of foam use something more delicate like a spotting bone). If after cleaning the next load, the door still leaks, you have a choice to make. Do you want to order a new gasket for replacement or spend the time and effort to attempt to adjust the door and/or gasket in order to affect a repair. Keep in mind there is a real possibility of making things worse by trying an adjustment. We will cover the procedure for changing a door gasket in this issue assuming you have a new gasket on hand. We’ll cover trying to adjust away the leak in the next issue.
The next step is removing the old gasket. You’ll need a screwdriver. Coat the screwdriver blade with some grease or Vaseline, then slide it between the side of the gasket and the retaining groove in the door into which the gasket fits until you touch the metal at the bottom of the door groove. Now pry up on the gasket until a portion of the gasket is out of the groove. You can then grab the gasket and pull it free of the door groove. In most cases the gasket is molded into a shape that allows friction to hold it securely in place. If however, the gasket is cemented to retain it, be sure to clean any large accumulations of cement from the groove. Let’s take the procedure for replacing the friction retained type of gasket first.
Grease the sides of the groove then take the gasket, center it around the groove. You will find the circumference of the gasket slightly larger than that of the groove. Push in only the top, bottom, right and left sides pinning the gasket equally around the circumference of the groove. Now start pinning small portions of the gasket from opposite sides of the door. Once the entire gasket is in place you will likely find that there are there are hills and valleys along the gasket surface. Distribute a film of grease across the surface of the gasket then take the handle of the screwdriver and press it firmly across the gasket as you move it around the circumference of the door. After a few passes, the rubber of the gasket should even out and be equally distributed in the groove. Re-distribute the grease across the gaskets surface and close and latch the door. Give it 15 or 20 seconds to seat. Then open the door and with a good flashlight and observe the grease pattern on the gasket. You will be able to see where the gasket is uneven by the absence of the continuous ring of displaced grease. If you find an uneven section of the gasket, use the screwdriver handle to distribute the gasket to eliminate the high or low spot. Once the gasket is even, close and latch the door and leave it for a few minutes before using the machine to allow the gasket to seat. Then bring solvent into the machine and check for leaks.
If your door gasket is the type that is cemented into place, plan to change the gasket at the end of the day since you’ll want to allow time for the cement to cure before using the machine. You can obtain gasket cement from an auto body shop or use silicone adhesive or contact cement available from hardware stores. The procedure is similar to that of Step 3 above. The difference will be in the initial fit of the gasket. It should fit into the groove easily and be very close to the circumference of the groove. Check the fit before applying the cement to see how the gasket will seat in the groove. Once the fit is established, follow the directions on the cement container. Install the gasket, close and latch the door and allow it to sit overnight before using the machine.
That’s it for this month, next month I’ll be covering gasket maintenance on other parts of the dry cleaning machine.
