Do you silkspan horizantal stabilizer and elevator before or after installation

[paulwells66]

Do you silkspan horizantal stabilizer and elevator before or after installation.
I have been told both from people and kit plans.
Tell me which way you do it and why.

Thanks

[Steve Berry]

I would do it before installation, just like covering the wing before installation, for all the same reasons. Much easier to work with a small part than the entire model all at once. Also, you don't end up with a "hard" edge where the covering stops just as it meets the fuselage, thus creating a stress point and possible break location.

Steve

[paulwells66]

thank you.  when I do finally install it do I cut away the silkspan for the glue joint or simply glue over it?

[john e. holliday]

I have done it both ways.  Depends on plane design.  The one I'm finishing now I covered everything I could before gluing together except for bottom of bottom wing and top of top wing.   It does make it easier to cover as much as possible before assembly.  In fact in Tom's book he shows overlapping silk span and poly span on the center sections of wings and stabs. 

[Brett Buck]

thank you.  when I do finally install it do I cut away the silkspan for the glue joint or simply glue over it?

  Glue over it. If you attempt to cut it away, you will certainly cause the problem you are trying to avoid (causing a stress concentration that may later fail), and you will very likely cut into the stab itself, further weakening it right where it see the most stress.

   Don't worry about the glue sticking, it will be good enough.

    Brett

[Ken Culbertson]

I don't think it matters much to the wing fuselage joint.  The stab joint gets more abuse so I usually cover it after installing but if I did cover it first, and I have, I will mark the fuselage line and not cover the part that joins out to about 1/8".   I use oversized fillets which I think look better and really stiffen the joints plus I stiffen the center sections of both the wing and stab.   I also glass the inside of the wing joint.  Probably overkill.

So in my case it is a matter of convenience not strength.  Doing it separate, especially on the wing, is much easier to do without adding warps.  Forget the wing, the Fuselage is 7.5 times easier to cover without the wing banging into everything.  Oh, I also only overlap about a 1/2" except for foam which I do about 6".
I think if you get 10 of us together you will find 11 different methods.

Ken

[Mike Griffin]

What Brett said.  I use Polyspan and overlap it over the center sheeting.  This makes the center of the wing where the fuselage is, really strong. 

Mike

[Steve Helmick]

Polyspan! Using silkspan on tail surfaces and flaps is just inviting warps.  Steve

[Serge_Krauss]

I silkspan everything before attaching the wing and stab. In salvaging a wing from a wrecked profile, I had a very tough time removing balsa at the wing joint. I do attach with epoxy, leaving the center wing area rougher and using epoxy with micro-balloons for fillet material. This is easier and more robust structurally, for reasons already mentioned. I see no reason to work harder for a stress riser.

[Air Ministry .]

Indeed . Out with the disc grinder !

A few layers of masking tape adjacent ( on Stab. ) and a rasp / bsteward file . Pays to mask the whole stab . unless youve cleared the whole bench , and its a good day .

Covering thru tends to traet it as a ' beam ' supported center .
Whereas covered after built , its kainda two canilevered things . So wants good stiff supporeted sides there for optimum stability . 

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A lot of info Via Ted etc on FOAM WINGS and needing covering right thru to avoid ' stress raisers ' at fuse. sides , to avoid wing shedding .
The Pre Reno nats Model Aviation articals and others go into this .