Tinnerman washers

It looks like Tinnermans were epoxied in-place above nut plates as added protection.

I know a Timmerman washer will be used under the screw, but I haven’t seen one used like this before.

This is a side view of the inside lip of a wheel fairing so you are looking at 2 places for screws. You don’t see the nut plate on the left side of the pic or the Tinnerman on the right side. As in 2 washers per screw.

Is this a common practice on wheel pants since they take their fair share of abuse?

Common, hmmm maybe not, but definitely used.

I don't know if it is common, but Paul Dye posted about this in the past decade to allow them to be hidden and a cleaner exterior look to the part. So, it is a known and accepted method of build.

I considered but lacked the incentive and wisdom to do the work.

Epoxy in place

I am epoxying in place all my tinnerman washers. But this person seemed togo up one notch and recessed them, and install extras near the platenut?

I dont plan to recess mine because I want maximum performance of the fiberglass underneath. Same reason I wont put them on the platenut piece of fiberglass unless the outer fiberglass is too thin. My reason for the epoxy in place is to keep the wear down between the tinnerman and the fiberglass piece, and one less thing to find when installing screws. JMHO YMMV

PilotjohnS said:

I am epoxying in place all my tinnerman washers. But this person seemed togo up one notch and recessed them, and install extras near the platenut?

I dont plan to recess mine because I want maximum performance of the fiberglass underneath. Same reason I wont put them on the platenut piece of fiberglass unless the outer fiberglass is too thin. My reason for the epoxy in place is to keep the wear down between the tinnerman and the fiberglass piece, and one less thing to find when installing screws. JMHO YMMV

Click to expand...

They are extras. The washers I’m asking about are on the inside lip.

Swing and a Miss (read the post)

That is really interesting and would like to hear from the builder on that.

Specifically why a countersunk washer was used atop a non-countersunk nutplate between the fastened layers. Aren't we just removing material unnecessarily?

I suppose one might argue for the anchoring of the nutplate by sandwiching the fiberglass between two pieces of metal. Although it doesn't look like it, do the attachment rivets for the nutplate penetrate the washer?

The upper rivet tail in the last picture seems a bit uber-squeezed and the orientation of the nutplate isn't ideal so perhaps it is just wild work?

Sounds interesting

Can someone give us a link to the Paul Dye method?
Thanks!
Steve Ashby

I don’t think the washers are countersunk. Tinnermans are very thin and it looks like the filler makes them look countersunk.

My thought was the builder used them was to “guide” the screw into the nut plate and reduce potential of damaging the fiberglass from repeated assemblies.

There is an article in the November 2022 Kitplanes by Bill Repucci named “Hidden Tinnerman Washers” that may be of interest.