Silkspan and/or Tissue Application

[Mike Griffin]

If you are covering with silkspan or tissue paper and the paper has a grain direction when you tear it, does the grain have to run span wise or can you apply it to the wing chord wise?  The reason I am asking is because I have some that the sheets are not long enough to cover a wing panel span wise but if I apply it with the grain running chord wise, I have enough to cover the panel.

Thanks
Mike

[Miotch]

Never used tissue, just silkspan.  And while I've read you should make the grain go span-wise.  But I've put it on running chord wise more than once and never noticed a problem.  I put it on pretty damp and it has always shrank and curved as I needed it to.

[Dan McEntee]

    Grain always goes span wise. If the sheet isn't long enough, center it and put the edge on a convenient rib, over lap the edge of the rib with it. Then continue with a new piece, overlapping the edge about 3/8" to 1/2". When you dope the covering, apply a little extra to that edge and it will feather sand away and be invisible. That's what us poor kids did woth shoe box tissue that wasn't long enough!!
  Type at you later,
   Dan McEntee

[Dave Harmon]

Some time ago I got some silk span from Brodak.
When I went to use it I found that the grain was going ACROSS the sheet so I did what Dan did except the paper was long enough to get to the center planking where I put on another piece....invisible.
Always make a test tear to see which way the grain goes.

[Perry Rose]

What kind of problem would you expect to see using the grain in the "wrong" direction?

[Dennis Toth]

If the grain is run cord wise you lose strength in the covering and could get tears or splits leading to a wing fold.

Best,    DennisT

[Dave Harmon]

What kind of problem would you expect to see using the grain in the "wrong" direction?

If  the grain is running across the cord....ie..L/E to T/E...the paper will shrink causing excessive sag between ribs.
With the grain spanwise, when the paper shrinks it will prevent excessive sag between the ribs.
On solid surfaces the grain direction does not matter....but put the 'shiny' side out....the 'hairy' side towards the work.

[Dave_Trible]

For some of the covering 'papers' around these days it wouldn't matter.  If you have some real silkspan, yes grain span wise.  (silkspan has NO slick side-the same both sides)  Japanese tissue has a slick side and usually a grain.  Some of the general purpose 'wrapping' tissue paper may have some grain-tear some both ways and see if it tears straight one way but not the other.  This usually has a slick side.  Doctor paper and such has no real grain or fiber direction so wouldn't matter-just plan on recovering in the near future when it stretches and shreds.  Tea bag paper has a grain and a very fine fiber mesh underneath.

Dave

[john e. holliday]

Yes any type covering with a grain needs to go span wise.  Now the Doc paper I use has a grain.  But I use it as a base covering with Mylar over the top.  I also do not wet the doc paper as the one time I did it was a mess.   Over solid surfaces it doesn't matter about grain.  That is my experience with coverings.  By the way How many realize that MonoKote shrinks better along the roll?  Oh and on D-tube type wing the grain will not sag beteen ribs in open areas but will cause sheeting on leading edge to sag a little.