Some basics tips on installing new Beckson window gaskets:
Site prep: Cover the port from up on deck with a blanket or towel and rig a droplight down below to be able to see clearly the black window gasket against the port body.
1. Place your new gasket in the sun to warm it up. This will make the gasket a bit softer, more pliable, and easier to work with. Remove the old gasket, and screen or backup ring, and clean and dry the window body grooves where both the screen and the gasket are installed.
2. Find the glue-joint seam in the gasket – where we have glued this length of extruded gasket material into a loop – and position the seam to be about top dead center of the window body. (If you put the seam anywhere along the bottom edge, the port might leak a drop or two at the seam.)
3. Find a polycarbonate (rigid plastic) or hardwood headed mallet. A metal hammer may crack the plastic. You will need it to force the rubber leg of the Beckson gasket ALL THE WAY DOWN INTO THE GASKET GROOVE that you have just cleaned. Finger pressure alone on the gasket will not force the leg far enough down into the groove. However, be careful not to damage the hinges or pin bosses or screens with the mallet.
4. With the seam of the gasket positioned near the top middle, begin moving across the top of the gasket groove to just before the hinge feature pushing in a ½” or so section of the leg into the groove as you move. Bang on the top of the gasket and drive it into the groove.
5. Continue clockwise or counter-clockwise across the top edge of the window, pushing the gasket into the groove and then using your mallet to bang the gasket into the groove moving about a ½ mallet width section of gasket at a time. By the time you get to the first corner you will have 8 or 9 inches of the solid rubber leg of the gasket firmly secured in the groove.
6. Here is THE KEY TO THE INSTALLATION. If you look carefully at the gasket groove in the first (and all) corners you will see it is narrower than the groove in the straight-aways. So, to get the leg down into the grove in the corners, you will need to stretch it as you are pushing it into the groove. Again, bang on it several times with your mallet to assure that the gasket is in all the way.
7. Here is a test of how well you did on the first corner. Look at the surface of the gasket in the corner. Is it puckered at all, or is it reasonably flat and level? If it is puckered or creased, stop right there, peel the gasket out of that first corner, and stretch it more this time as you force the leg into the groove. No need to continue if there is a pucker because you will not have enough gasket left to do the last corner. In addition, it makes sense. Since our lens is very flat on the surface that is pressed against the gasket, you would want the surface of the gasket to be uniform also.
8. So, continue around the window body pushing the gasket into its groove in the straightaway and stretching as you push it in in the corners. Continue to use your mallet to bang the gasket as you go. CLEAN AND DRY THE SCREEN OR BACKUP RING AND INSTALL IT BY SLIDING IT INTO ITS GROOVE WITH THE SMOOTH SIDE FACING YOU AND THE RIDGES SLIDING INTO THE SCREEN GROOVE AFTER HALF OF THE GASKET HAS BEEN INSTALLED. When you have completed the gasket installation, use your mallet and firmly bang the gasket all the way around the port to make sure the leg is completely into the channel. Inspect visually to confirm.
9. Now you are ready to close the lens. Before you do that, back off on the knobs or lever cams so that they will swing easily over the closing forks with your hand pressure on the lens. Then tighten the closures. BE CAREFUL NOT TO OVERTIGHTEN, especially when using the lever cams. The distance from the lens to the gasket will be about 1-1/4″ to 1-1/2″. Tighten just enough to trap a piece of paper or dollar bill between the lens and the gasket. Enjoy your leakfree opening port.
After the first one, others will be much easier and take less time. It is mostly in the technique and in knowing some of the design elements of our windows. Over time, you will be able to close the lens further and further as the gasket begins to yield to the compression and settle into its new home.