Washers under screw head?

[skelrad]

For areas that are painted (rear baggage bulkhead panels, seat pans, etc) and attached with nutplates and screws, do you usually put a thin washer under the screw head to give the screw something to turn against instead of the painted surface?

 

[AZSteve053]

Some people use thin nylon washers under the heads to protect the wear surfaces, a tight fit to the threads makes for easier handling which keeps the washers attached to the screw near the head.

 

[rocketman1988]

For areas that are painted (rear baggage bulkhead panels, seat pans, etc) and attached with nutplates and screws, do you usually put a thin washer under the screw head to give the screw something to turn against instead of the painted surface?

I did. It helps but will not eliminate the eventuality of paint damage. In areas where I wanted to avoid paint damage and were not structural, I used nylon washers.

 

[Amadeus]

Some people use thin nylon washers under the heads to protect the wear surfaces, a tight fit to the threads makes for easier handling which keeps the washers attached to the screw near the head.

Nylon, yes, just like on wheel pants.

 

[Walt]

No nylon, bulkheads are primary structure.

 

[PaulvS]

No nylon, bulkheads are primary structure.

Do you usually put nothing there (i.e. steel screw head bearing directly on softer aluminum) or do you use a steel washer?

 

[TASEsq]

Funny, I just ordered myself some of these for all the cockpit panels - nylon washers but they don’t fall off the screws.

https://www.digikey.com.au/en/products/detail/essentra-components/16FWRT008032/9676846

https://www.digikey.com.au/en/products/detail/essentra-components/16FWRT006032/9564203

 

[Walt]

Do you usually put nothing there (i.e. steel screw head bearing directly on softer aluminum) or do you use a steel washer?

No washers needed, but I do like and use quite a few AN525 washer head screws, loose washers are a PIA.
2024 aluminum is not considered 'soft'.

 

[rocketman1988]

Do you usually put nothing there (i.e. steel screw head bearing directly on softer aluminum) or do you use a steel washer?

I used steel washers there.

 

[Mikeyb]

I followed the plans with just screws. I can’t find a single spot where a screw disturbed the paint outside the screw head even on panels I have removed many times. I did use single stage polyurethane paint

 

[rv6n6r]

Nope

 

[plehrke]

I only used washers up against fiberglass parts when attaching with screws into nut plates. There I used mostly the countersunk washers since they are on outer mold line.

 

[PhatRV]

I put the stainless steel washers under the screws if they touch fiberglass surface. This makes it easier for me to remove the screws. The screws tend to dig down into the fiberglass and making them difficult to remove, without the washers.