Originally Posted by Crozzie

Yes, ptfe sheet is what I would use in the same situation, cuts easily
while thinking about your release wax paper mentioned in post #413, have you thought about using the film sold by Balsa Cabin for plan protection? nothing sticks to it, it's very thin , and...cheap!
Trev

No more purchasers I'm afraid.Day off tomorrow,so I hope to get the first two layers on.
Stuart

Preparation.Trial slot cut in the root and filled with expanding foam.Packing tape wrapped around and waxed.
I then realised I needed something to measure against;I should have cut the bottom plate bigger.So a piece of 2mm board used to make an edge.The roots tack glued to this.
A piece of waxed paper tacked to the top plate and waxed twice.(hence the two pics)
The whole thing mounted on a turntable so I can rotate to measure.
The epoxy containers felt a bit cool,so I've put them to warm.more to follow.
Stuart

Task complete.Cloth weighed 60g,resin mixed to that weight.
Surface wetted evenly and cloth laid on.The roller is home made;the loop side of some self adhesive velcro on a seam roller.I'd seen something similar on carbon.mods site,works well.
More epoxy,more cloth,rolled again.The roller picked up very little resin.
Remaining epoxy brushed on distributed and excess removed with a card.
Top plate fitted,clamps attached and tightened evenly,spacing checked.It didn't need much adjustment,but seven identical clamps would have been better.
Not much excess epoxy; next time I'll weigh 59g!
5 pairs of gloves to take these pics!
Stuart

The result.Press came apart very easily.Some epoxy got between the packing tape and the foam in a small area,probably because I didn't bother sanding.Otherwise I regard this as a good result,the process is not as difficult as I feared.Top layer next.
Stuart

Nice one! Welcome to the 'wonderful world of composites'...

Originally Posted by Shedofdread

Nice one! Welcome to the 'wonderful world of composites'...

Thanks Richard,"I'd never have made it without you"as the saying goes.
One curious thing.When the press was tight the tape I'd wrapped around the edge looked slack,so the foam was obviously being compressed.Now it's out this slackness seems to have disappeared,which implies a certain amount of recovery.I don't have any verniers so can't get accurate measurements,but I'll have to get some to see what's happening.

This has given me the confidence to tackle the canopy on the VII,then maybe the nacelles,air intakes on the underside...............
Regards and many thanks Stuart

Top surface.lessons taken from this-
I need a scale that weighs fractions of a gram,I had to guestimate 10% of 4g(half weight of the fabric.)
The powder thickens the resin quite a lot,again accurate measuring needed.
The slightest dust particle shows,cleanliness vital.Also this fine fabric sheds easily,masking tape around the outline before cutting out.
Don't skimp on the resin.A couple of places where the weave shows.
Stuart

Not much progress lately,had a dose of the lergi!
Managed to do a bit last night/this morning.As on the trial I filled the slots with foam.The plan is to redrill
these when the glassing is done,using the templates.
Some balsa pieces fitted around the edge.I don't think these are really necessary ,but better safe than sorry.Square pegs in round holes,nice tight fit without glueing.
I realised I needed a way to keep the centre pivot clear of epoxy.Again with hindsight these should have been drilled after glassing.So again used the templates to drill holes in the press boards and inserted 6/4mm tubes.A dab of petro jelly over the holes till I get the first two layers of cloth in place,carefully open the weave to allow the 4mm rod in and clamp.Plenty of petro jelly on the rods and hope for the best.
Stuart

First layers on .I cut out all the glass before starting.Each surface is getting 2 layers of heavy,2 of light and one tissue.The first pressing is two layers of heavy and one light.The idea is to wet and dry this and then add a layer of light cloth plus tissue,using the powder in the mix.
The rods seem to work ok,I'll keep moving them till the epoxy has set up.
Stuart

Result.This will do I think.Just one spot top right where the weave shows slightly.

To keep the model in pitch trim whatever sweep angle, put a slight dihedral angle in about a quarter of a wings length from the tip.As the wings are swept this gives an increasing "up elevon" effect to counter the "nose down" effect. I have done models this way many years ago.

Originally Posted by macboffin

To keep the model in pitch trim whatever sweep angle, put a slight dihedral angle in about a quarter of a wings length from the tip.As the wings are swept this gives an increasing "up elevon" effect to counter the "nose down" effect. I have done models this way many years ago.

Interesting idea.Do you have any more details of the models,I'd be particularly interested in the airfoil.
Regards Stuart.