by Ken Rajesky, Hearth Industry Expert
Before you start any procedure involving your product, its important to first check your manufacturers instructions to ensure that the cleaner or the method that you plan to use complies with their requirements. This is especially important if the product is still under warranty. This information will also tell you what size gaskets to use, and how much is needed.
Always make sure that you have the proper safety equipment such as gloves or glasses. Adhesives may be caustic to your skin, and your eyes are irreplaceable. We recommend that you have the following tools:
Time to Replace the Gasket!
Small ball peen hammer
Dead blow hammer
Thin bladed screwdriver
Gloves, if you are sensitive to adhesives
Questions that frequently arise are:
Is that gasket material made of asbestos?
What type of glue should I use?
First, all modern stove gaskets are made of fiberglass. Fiberglass gasket is available in many sizes, and density. The combination of thickness and density will depend on the application on the product. A frequently opened door may need a larger, more-dense gasket for a better seal and durability. A glass gasket, for example is typically not large or dense because it is not required to be large, nor is the gasket disturbed very often.
Gasket adhesive also varies. There are many types available, and most of them are okay. I highly recommend Heat Safe Gasket Cement. It is available in a small tube and will take care of most stoves. It is easy to work with, flows nicely from the tube, and keeps the gasket tight to the frame or door. It is an excellent product. If you cannot find this brand, look for a cement which flows easily - some tends to harden in the tube.
Gasket and Heat Safe Cement
1. First, clean the groove by stripping out the existing gasket material. If you are lucky, it will peel off easily. If not, see Step #2.
2. OK, if that didn’t work well. So, put on your mask and goggles, grab your screwdriver and ball peen, and start tapping away at the gasket and glue in the same manner you would use a wood chisel.
3. After completing this fun task, check the groove. It should be uniform in shape. If you are dealing with a cast iron door, sometimes the glue has the same grayish color as the casting and blends in. Run your finger along the groove. If you feel a bump or irregularity, then you have some remaining glue. Chip it away.
4. Now, take your shop vacuum out and clean away all of the debris before you begin to install new gasket.
5. Before you apply the glue, take the gasket and lay it into the groove. Leave a little extra hanging out, and cut the gasket. This will make the installing part a little easier.
6. Now, apply the glue to the groove, and don’t be cheap with the material!
7. After that’s done, run your finger through the goop and be sure to spread the glue evenly through the groove, taking special care to get the sides of the groove covered with glue.
8. Now, if the doors gasket runs in a circle, in other words there are no open ends, start placing the gasket into the glue-laden groove in the middle somewhere on the door. Do not start in the corner as the gasket may come out prematurely when started in a corner. A little bit of masking tape on the ends of the gasket helps prevent the gasket end from fraying.
9. As you place the gasket down, do not stretch the gasket as it will decrease the diameter of the gasket. Take a clean gasket and stretch it out. See how it gets skinnier? Now, push it closer together. See how it gets fatter? If you make the gasket skinnier, it defeats the purpose of re-gasketing. Just lay the gasket down, and give the gasket a tap down as you go along. When you get to the end, cut to size and place a little masking tape on the end to prevent fraying.
10. Allow the glue to set up, and then place the door on the stove. You may have to readjust the latching mechanism, as your new gasket is thicker than the worn out older gasket. Take your dead blow hammer and give the door a tap around the perimeter.
11. Now, open the door, slide a piece of paper between the door and stove body, and close the door. Now, try and pull the paper out. If it does not pull out easy, you have a tight seal. Do this around the perimeter of the door. You may need to adjust the latching mechanism.
12. If you’ve adjusted the mechanism, yet there’s a place on the door where the paper still pulls out easily, then mark that spot with some chalk on the outside of the door. Pull the door off because you’ll need to buildup that area.
Why did this happen? Because all metal expands and contracts. Sometimes, it does not contract to the original location. That’s the purpose and reason for gaskets—-to make up this distance, maintain the seal, and give the operator control over the amount of air entering the stove.
13. While the glue is still wet, pull up on the gasket in that area. Take some smaller diameter gasket, cut it to length, place it in the groove, add a little cement on top of it, and push down the larger gasket on top of this new layer. 14. Now, do the paper test again. If the seal is okay, congratulations! If not, you’ll need to keep building up the affected area until the seal is tight.
DONE, now you’re ready for another season.
Woodheat.org maintains a good article on gasket replacement at: