Firewall grommets?

[House Money]

Hi all, hope you all had a nice Christmas!

I tried searching but could not find an answer to my question. I'm in the process of fitting the firewall pieces and have noticed that there are some sizeable gaps around the frame tubes where the firewall parts meet. I see nothing in the manual addressing this, does anyone have any suggestions on how best to seal these up? Grommets, caulk or some other sealant?

Thanks, Gary

[Frank Pav]

I used a product called Pro-seal to seal all of the rivets and gaps in the firewall of an airplane I built . The product is fuel resistant and fire resistant. It's mixed with a catalyst as a thick paste and can be applied using stir sticks. Dries in a reasonable time and is very tough.

[Robodent]

I used black caulk on the inside around the tube area. I didn’t want it to look ugly on the outside by the engine. Rob

[FF33rod]

The hot rod has the same situation. Looking back at an April 2018 version of the HR manual, there were aluminum pieces that you siliconed into that area as shown in the attached manual snapshot. However, I never received those pieces with my Fall 2018 kit.

Also, looking at the new Gen2 manual, any reference to that is gone. I guess one could fabricate something if you wanted to.

However, that doesn't bother me as much as the big gaps in the firewall to body interface - the radius of the top corners aren't the same for example. That's going to be an interesting challenge to look professional.

manual 2V.jpg

[AC Bill]

I used a brush-able automotive seam sealer. It was grey in color, so wasn't stand out obvious against the aluminum.
Used this on my rear cockpit bulkhead areas, around the seat belt anchors, any gaps in the footbox aluminum, etc, etc. It remains flexible, through all temperatures, waterproof, and is very resilient.

[House Money]

Thanks for the suggestions, I'll have to research these products. In some places I'm looking at gaps about 3/8ths of an inch so I think I'll need something rather think - putty like most likely. Or, maybe one or more of these products could be applied in layers?

Gary

[AC Bill]

For the larger gaps, use an automotive aluminum tape. If it is near a heat source, you can use the DEI heat tape. They adhere well.

[rponfick]

I just used black silicone sealer.
Ralph