Using Permatex Ultra Copper High Temperature
RTV Silicone To Make A Permanent Gasket

Editor's note: This article was written by Frank Smith, a member of the Big Green Egg Forum at who posts as Frank from Houma. We are pleased to publish this information for the ceramic charcoal cooker community. The contents of the article belong to Frank and any questions or comments should be directed to him at the Big Green Egg Forum.


The following discusses an alternative gasket replacement for a ceramic cooker. I personally have tried Felt, Nomex and Rutland gaskets with the following observations:

Felt – Replaced the OEM gasket with a felt gasket and continued to have issues with the gasket frying.

Nomex – A good alternative but after about 1 year the material seemed to harden and I started having adhesion issues. Many have installed the Nomex gasket and are quite pleased with the performance.

Rutland – Also a good alternative and many have installed a Rutland with great success (see: How To Install A Rutland Gasket). The issues I had with the Rutland were twofold. One was the fact that although one kit is more than satisfactory with a Large BGE ending up with one seam, the XL BGE required two kits yielding two seams where problems are more likely to occur. The second was that fact that the rope like material started to unravel at the seams, likely due to my failure to install properly.

Cotronics – I have no experience with this product but I understand many are pleased with it.

Ultra Copper – I’m very pleased with the Ultra Copper gasket and the following will describe the method I used to install the gasket.

Ultra Copper High Temp RTV Silicone Gasket Maker comes in a tube and is readily available at any auto parts store. It can be installed one evening and used the next day and withstand temperatures of 700°F. It hardens to a consistency of a dense rubber (not to say a consistency of a bowling ball). It provides a nice cushion when closing the dome.

I wanted a full width gasket on the base with no mating gasket on the dome so I made a jig that would ride on the lip for the bottom band to ensure the gasket was the same depth on the base. The jig opening was sized to the width of the base and the depth approximated the space between the dome and base when the felt gasket was in place.

Ensure that the jig is tight to the base thickness to avoid applying gasket material to the inside or outside of the base. Fired the mini up the following day with a bunch of chips for smoke and ran the dome temp up to 900 without any issues. The only smoke present was smoke coming out of the dome.

After six months of using the Small and Mini with no issues, I decided to put the gasket on the XL. After cleaning the base, I made a jig to fit the XL – note the gap above the base. After making the jig, go around the circumference of the base to ensure it will easily travel to whole distance – I found some minor variations in thickness and had to widen the gap slightly. Keep a rag and some acetone handy to wipe any gasket material from the inside/outside of the base – comes right off and comes off easier if the cleanup is performed immediately.

Lay down enough gasket material to provide for full coverage. After getting started, I found that instead of one thick bead in a straight line, it was better to weave the bead back and forth across the width of the base. I also found that working in increments of 1-1/2 to 2 feet worked well. When starting a new increment, lay some material on the previous section to ensure the two sections are tied together seamlessly.

You should be pushing some excess material to ensure full coverage.

I went over a spot after 10-15 minutes and the material had begun the curing process and ended up with a section that was rough – the material just wasn’t as pliable/liquid after 10-15 minutes. The fact that it was rough didn’t bother me, but there was smoke coming out in the area during the first low and slow. Additionally, I ended up with two low spots that I didn’t recognize until after the first low and slow.

Low spots or areas that need additional attention were easily fixed by cleaning with water, cutting back a small amount of the base material with a sharp knife, and following the same process for adding material with the jig. Low spots are easily identified during the low and slow and evident by the smoke on the gasket.

Some suggestions:

The amount of material required: Mini – One tube, Small – Two tubes, XL – Five tubes. I would purchase and extra tube in each case and keep the receipt - you can always return the unused tubes. Better to have enough when you get started than not enough but if for some reason you run out, you can always come back and add to the gasket the next day after curing.

The following is a link to some safety data. Permatex Gasket Safety Information I recommend you read it and decide if you wish to use it. I obviously have no qualms with using the product as well as many others who use it to install Rutland gaskets.

Good luck and happy Eggin'
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