Vans Spinner Installation Screws
 

I am fitting my Vans FB spinner and I see in the instructions Van says you can use round head or CS #8 screws with recessed washers. For the CS screws he says to use a #19 CS to accommodate the recessed washer. To CS deep enough to accommodate the CS washer, you will end up enlarging the screw hole since the FB is not thick enough to really accommodate the CS washer. What have others done regarding this? Is there some other washer that works better, are washers really required, the CS can be made deep enough to accommodate the screw only but that fastening may not be strong enough.

SPINNER SCREWS
 

Looks like the best bet is the truss head 8's for this application. I questioned my A/I buddy about this very thing over the weekend, and he seemed to think it was a better choice to install the truss head screws. You could always change over to the C/S screws later if you wished. At sun and fun this year I paid close attention to this issue, and it seems like a 50/50 split in the choice judging from the ships that were on the field. I noticed a few cracks around some of the planes spinner screws regardless of how they were attached. I noticed no smoking screw holes with either, but again they may be out there.

HTH...Chris

I would definetly use the CS screws and washers. The enlarged countersunk holes (they don't enlargen significantly) will be filled by the washer and it will actually self center itself. I don't recall doing anything special and the holes all came out fine and the washers fit in nicely.

Without the washers, the holes will eventually erode and you will have more repairs to deal with. Loose spinners can get very nasty.

Roberta

This has not been my experience
 

I used truss head screws on my 6, only 80 hours on them, but no problems. My Bucker spinner has truss screws as well, well over 500 hours on them, no issues.

I concur with Roberta - I like the look of the countersunk screws in the washers, and the hole enlargement is really a non-issue,as the washer and screw center themselves. In fact, that might actually help to relieve pre-load and stress - kind of like a floating nut plate. Anything you can do to relieve stress out there is a plus!

Paul

Regardless of screw type
 

Regardless of screw type put a thin bead of RTV on both bulkheads to insure that the spinner gets locked in place. Some people use Proseal to cure spinner movement, the RTV is more of a preventative measure. Good luck.

Disagree with RTV/Proseal on Spinner
 

I have a composite prop which is subject to being retorqued and that is the exact reason I went with RTV rather than Proseal as is sometimes suggested. The RTV does not provide a strong enough bond to hinder spinner removal (well okay a little bit) but it fills voids and prevents movement.

My spinner started to show signs of movement at about 10 hours maybe less. I checked the spinner/bulkhead interfacefor voids but found none. I tried a thin coating of RTV on the bulkheads at the suggestion of an AI bud. It stopped all movement.

When reinstalling the spinner, I just rub off the old RTV with my fingers and put on a new layer.

This has been my experiece anyway. Good luck.

Flat head screws, countersunk spinner holes, dimple washers, no seal
 

Hartzell C/S non blended airfoil - Flat head screws, countersunk spinner holes, dimple washers, no seal, no problem. Lube the prop hub at annual. Approximately 400 hrs on airplane.

Bob Axsom

Same as Bob, 800 hrs and no problems at all with the spinner, screws, washers, etx. Just lucky?