when assembling the firewall, should the pieces be bonded with hysol when riveting together? or should it be riveted dry and firewall sealant applied over top of all edges?
thanks, ken
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when assembling the firewall, should the pieces be bonded with hysol when riveting together? or should it be riveted dry and firewall sealant applied over top of all edges?
thanks, ken
Ken,
Hysol is a not very flexible as sealant. If you do get a leak or need a repair at some later time, it will make the job very difficult. I would go with a more flexible and removable product.
You might consider attaching the footwell pockets with screws and tinnerman nuts. It will make access to the brake pedals easy without having to remove the entire motor and firewall.
Use firewall sealant during assembly.
To make things look pretty, tape along both sides of the joints where sealer will ooze out. After you rivet, wipe up the excess and remove the tape for a clean line.
John
John,
What do you think of using the RTV sealant that was used to secure the fuel tanks? Or another RTV sealant? I've used the Red RTV before and it is supposedly resistant to high heat, not sure how high though...
Thanks,
i like the idea of using removeable footwells for maintenance. i have firewall sealant that should work fine.
ken
When I was building a box into my firewall I went to Van's RV site and purchased a Proseal 700 firewall sealant that I believe is rated for 2000 degrees. RV builders have been using this for many moons.
http://www.teamkitfox.com/Forums/showthread.php?t=80
The Dow 739 adhesive that you put use for bonding the tanks is probably not rated for extreme heat. However, being that it is between layers of stainless steel that act like a huge heat sink, I don't think you will have any problem. For the more conservative builders there are lots of firewall sealants.
Spruce sells a good product, albeit pricey.
http://www.aircraftspruce.com/catalo...l2000caulk.php
The problem with the red high temp stuff from the auto parts is the same as for many other RTV products. If it smells like ammonia, it will corrode aluminum.
John
I know this is an old thread, but I just ran across it. I was wondering if anyone has actually used tinnerman nuts or nutplates to assemble your firewall rather than the recommended rivets.
If you have - are you happy with the results?
Were you able to get a good seal with this method?
Any pros or cons?
Any responses would be appreciated.
Bob