Holding down sheet while glue dries

[Don Fry]

I use lead shot in cloth rolls to weigh sheets to structures while the glue dries, great for curved sheets like leading edge sheet, and does not distort the sheet as pinning does. Am about to buy more, and on searching e bay and the like have found in the last 20 years it has become expensive. I see on e bay that people sell steel shot, and it is a fraction of the price. Less dense than lead, but does it do the job? Anyone any experience of steel shot, or even views on how to attach leading edge sheet without stress. Stress leaves callouses on the soul.

[Steve W-O]

Posted by Donald Fry on 18/04/2012 19:22:48:

I use lead shot in cloth rolls to weigh sheets to structures while the glue dries, great for curved sheets like leading edge sheet, and does not distort the sheet as pinning does. Am about to buy more, and on searching e bay and the like have found in the last 20 years it has become expensive. I see on e bay that people sell steel shot, and it is a fraction of the price. Less dense than lead, but does it do the job? Anyone any experience of steel shot, or even views on how to attach leading edge sheet without stress. Stress leaves callouses on the soul.

Ziplock bags full of sand work, so steel shot should be better

[ken anderson.]

hello donald..... i tack the leading edge with good old super glue(cyano)..and the rest with ordinary wood glue..... with the occasional dab of cyano.....

ken anderson ne..1 ... cyano dept..

[Peter Miller]

I use map pins at the leading edge and big club or Argos catalogues for the rest of the wing whe the whole surfaces is sheeted or if the sheet only goes back tot he spar I use bulldog clips to hold it to the spar.

[Steve W-O]

Posted by Peter Miller on 19/04/2012 08:22:03:

I use map pins at the leading edge and big club or Argos catalogues for the rest of the wing whe the whole surfaces is sheeted or if the sheet only goes back tot he spar I use bulldog clips to hold it to the spar.

Also use bulldog clips on the spar (with scraps between the clip and the sheet) after holdinf the leading edge down with masking tape.

[Phil Brooks]

I have experimented with the following method, though have not yet used it in earnest. Paint the ribs with aliphatic resin and allow it to dry, then set your covering iron to high and iron the sheet into place. It makes a very strong bond, and I'm planning to use it on a large fully sheeted wing for my Cessna 182 sometime soon. This is not an original idea, I read it somewhere on this forum, but can't remember the thread.

[Richard Wood]

Hi Donald,

I also often find glueing LE sheeting from LE to spar awkward if tried to

complete in a oner.

Other builders will have other good ways to do this but I attach the sheet

initially just to the LE & forward few mm of the ribs with PVA or aliphatic &

let it dry. When dry glue the rest of the sheet back to the main spar &

pin down to dry.

Wipe away any excess glue between LE & sheet as it can be a pig to sand.

 

 

 

 

Edited By Richard Wood on 19/04/2012 10:31:57

[Don Fry]

What is aliphatic resin? I take it this is different to the yellow sanding frendly stuff we all use on structure glueing.

[Richard Wood]

Aliphatic resin is a yellow water based glue very similar to PVA.

It apparently has better 'grip' when wet than PVA.

I personally prefer PVA as it seems to be slightly less brittle when set.

Aliphatic is said to sand easier than PVA but there isn't much between

them.

[Peter Miller]

Yes, the ironing down technique does work but you may make the wood go black in places. You also need to apply the glue, lay the sheet down to get glue on both surfaces and then lift it, add glue to any missed spots and leave to dry.

[Don Fry]

Re aliphatic resin. Am I getting this right that you can apply it, let it dry, then reactivate it with a hot iron like solarfilms' balsa lock works on solarfilm.

[Area 51]

Bags of sand!, couple of freezer bags to keep intact but it applies an even force and moulds to curves nicely.. Hope this helps...

[Peter Miller]

Yes, the Aliphatic becomes heat senstive BUT it only works once. The heat polymerises the glue and that is IT.

[Phil Brooks]

My small scale experiments so far have been very successful in applying the aliphatic to one surface only, but I'll defer to Peter Miller's greater experience and wisdom.

[Don Fry]

Thank you for the aliphatic resin trick. A relevation.

Re the sand solution my thought is that the small dense lead rolls hold the sheet down, but are small enough to see the job/joints and when done I walk away, secure in the knowledge than the job will be good in the morning. No stress. Does a sand bag not hide the joint. have not tried it, but being idle, any thoughts anyone. Shifting my idleness, from the internet, I found relative density figures, lead is 11300, steel 7850, loose sand 1440. I worked out that for 2 mm loose shot about half its volume is air, sooo relative density becomes (about) lead shot 5500, steel shot 3900, sand 1440. This gives the relative radius of the weight rolls used to squash down the sheet is, in savage rough terms as lead 1 unit, steel not much more, sand 2 units. So good bye lead, too dear, perhaps steel, half the price and near as good, but sand, and I never thought of it, is free.

[Richard Wood]

As Steve stated earlier, masking tape is very hard to beat to secure LE

sheeting to a LE strip. Even pressure can be applied along the whole

length to produce a close fit. Remove excess glue before taping.

[Biggles' Elder Brother - Moderator]

The ironing trick works with PVA as well.

BEB