On my Max Caddy I have 3 gaskets. Door, ash pan, and heat exchanger. I did the door and ash pan last year and they are fine but I noticed I was hearing a bit of a whistle at the bottom of the heat exchanger door during hard burns last winter. So, while replacing a few bricks and otherwise cleaning the furnace up for spring, I decided to replace the gasket on the exchanger door. The old one didn't look bad at all as it's not opened often like the door would be but for ten bucks, why not. What I've noticed is, I can still pull a dollar bill through too easily even with the new gasket. I put chalk along the metal edge to check engagement and it's definitely contacting the gasket all the way around. It's just not a tight seal like the door and ash pan are. Should I try a different gasket? (I'd hate to fight this one out after cementing it in as it's biting hard... Or should I not be concerned?
I'd want that sealed well personally...hate to have back puffs from it. Is it an SBI gasket? Sounds like buying aftermarket gaskets can be a crapshoot, as far if the size/density is correct, or not.
The last SBI gasket I bought was generic. Not sure who they use for a supplier. Kind of like Motorcraft filters being made by Purolator. I might call them tomorrow and ask them about it...
That's the problem, the aftermarket can't always get the size/density/material right to match the OEM. Some designs are flexible and some require exactly the right thing. Then there's the installation variability, how much you bunch up the gasket when setting into a thick or thin bed of RTV. It would be great if there was a standard but there is not. Kinda like the diameter of the flue collar.
Just coming back to this now as I don't want to wait til burning season to figure it out. I'm thinking I'll have to pull it and redo it with the OEM rope. It's probably going to be a B removing the new one that's in there with brand new gasket cement holding it in place. This time I'm going to try bunching it as it lays in the groove too. I could have done that last time and it probably would have been perfect but the instructions said not to. Live and learn I guess. It was only 10 bucks so not the end of the world to pull it and toss it. Just irritates me when I make a mistake...
https://www.ebay.com/itm/318481910013?_skw=Silicone+RTV+4500+FDA+Grade+High+Strength+Silicone+Sealant,+Black+(2.8+fl.oz)&itmmeta=01KVRC9QFEM5Z3N0H4KE71EKG9&hash=item4a270048fd:g:LsgAAeSwtAZqNqCL&itmprp=enc:AQALAAABMGfYFPkwiKCW4ZNSs2u11xDgq+7lmt9APj2Smp31G6xEFjF+/7FP2VawBQBHIc5GTRkGZjctr7l6r0lb4uuKYWUWrx/EFae04WKVx9Th+E7/EajE1GZJtyDPOeEQ3YUwo4CEkpV8JB3qCo5H6REXV/rF18zIsj6QYjwCwYuYoyv5oAajYem/8Q4dUManzHJRvsfnnbfru4HHeDopny5MEdZ6elHe8rwJFkIB9FY/9pEoAhKq/yGKVl49lDPLRbKC+MoZicXaQ/O5UBccuHHLE/RjptN+uRHFx/yeTPIlhiyMhKUXxS5pdRu8d4HZmL3ZA55D6pnjQmorxY32dUYZjAkEDKzsD7fLYtYwpsavBhpscQQskTcnP/QpaelxthhmPpiBCiwOgMyi9PC1t/x6fBk=|tkp:Bk9SR-r3pozeZw I would use this instead of cement. You can build some depth in the channel. I gave up on cement long ago is it gets hard and makes the gasket hard and somewhat brittle as well. I have had great success with this particular brand, even build it up level where the ends meet.
If you have the correct gasket material, bunching it could cause problems too. It's supposed to be just laid into the mud. Oh and I would always use high temp RTV from the auto parts store. Black is fine. Red looks bad when it spooges out.
