Trent's RV14 Build: 38-29 -> 30: Canopy Fibreglass Fairing - Round 3

First Layer - Ply A & Ply D - Black

Prior to the fibreglass layup, a layer of 'sactificial masking tape' was added over the top of the electircal tape, to allow any resin or cloth which bridges onto the tape to be removed before it cures.

The first step was to layout the first layers of glass cloth on top of a piece of gladwrap - these were left oversize. They then get saturated in black tinted resin. A top layer of gladwrap is then applied making a sort of sandwich, then it is trimmed to size according to the template. The Ply A (curved) pieces are left and right - after being cut to size, they get the top piece of gladwrap removed, then they are applied to the canopy. This means that the side which is up on the bench, has to be the side which gets applied to the canopy. It would be easy to get these backward, and have 2 left or 2 right pieves - and the inevitable massive resin mess - so i made sure to label them carefully.

I found the best tool for squeegeeing out the resin into the cloth was a hotel key - these work great.

Labelling is important so i didn't end up with 2 left pieces and a resin mess!

The best kind of tool is a free tool - and good advice when working with resin.

5% opague black pigment was added to the resin

The hotel key worked really well - it took a little bit of time for the resin to soak into the cloth.

The top sheet of gladwrap was applied over the soaked cloth

It was then cut to size according to the template.

Once the pieces were cut and saturated, i used a foam brush to apply a layer of raw resin to the canopy surface to accept the glass.

The top sheet of gladwrap was removed from the pieces on the bench (which were the inner surfaces), then the pieces were applied to the canopy. Once applied, the other bit of gladwrap was removed and the pieces moved so the edges were *just* up against the tape.

These were left to partially cure - around an hour - until they were still tacky, buy no epoxy transferred to my finger.

Voice from the future:
If i were doing this again, I would have used some micro baloons filler, tinted black, along the edge of the final fairing at this point. The finished edge formed by the fibreglass layers, was not very sharp. I ended up having to reapply the tape, moving the fairing line a little, and using micro to get a nice edge. I think i could have removed the masking tape, then applied some micro to get a better edge.

Second Layer - Ply B & C and the many little strips

Next up was to actually do the layup - all the fibreglass pieces, as well as the peel ply, were all laid out ready to go. As per the plans, and also the excellent Van's video series, i applied the Ply B & one of the thinner pieces overlapping Ply B. The plans are a little confusing on this, but seem to show the 'first narrow strip' on top of Ply B & C. In the video, Scott adds the first narrow stip over Ply B, then adds Ply C over both of these.

In any case, i followed the video, and added the 'first narrow strip' over Ply B, then added Ply C on top. I figured this would capture the end of the first narrow strip better, and Scott knows what he is doing!

This shows the 'first narrow strip' on top of both Ply B and Ply C.

For future builders - the plans have you cut the straight pieces from the cloth, parallel to the weave, with the largest being 1 5/8" wide. When i pulled off the masking tape, there were many strands lost when pulling up the tape. This was because the cloth was cut parallel to the weave - if this had been cut on the bias to the weave, then this would have had a much nicer edge. Note that the initial Ply D (the one coated with black resin), was cut on the bias for this reason, but the plans do not call for the outermost thickest strip to also be cut on the bias (but i reckon they should!).

Ply B laid down, with the 'first narrow strip' lad over the top of Ply B (and will be under Ply C).

Ply C laid down, on top of both the 'first narrow strip' and also Ply B.

To start building up thickness, the pieces got wider and wider as the curve was filled out, and i used a 4" radius tool made from some scrap to check how i was going. If a section needed more filling out, i added a thinner piece in the centre of the curve to bulk it out a bit.

The 4" radius was quickly met at the edges of the canopy, where it started to curve around the sides.

As it moved to the middle of the canopy, it started to show a gap and needed more cloth thickness.

By the centre, it needed quite a few thin strips to build up the thickness.

In some places, a small strip was added over the top of a thicker strip, to build a bit of extra thickness in the centre of the layup, in order to get a nice curve.

Eventually, the curve met the 4" radius along the whole fairing and i was done applying cloth. I used a 'fibreglass roller' to ensure all the layers were pushed down and i had not incorporated any voids.

Once the layup was done, i used a foam brush to add a 'flow coat' of raw resin over the top of the layup, to help fill the weave with resin.

The 'sacrifical' layer of masking tape was then removed, so that minimal resin / cloth was located on top of the tape (to save sanding later). As mentioned above, when i pulled the sacrifical tape, it pulled up quite a few strands from the edge of the largest 1 5/8" strip of cloth. If i were doing this again, i would have cut this largest strip on the bias, to help prevent these strands lifting up like this.

Here you can see how the tape pulled up quite a few strands along the edge of the thickest strip of cloth.

The purpose of the 'sacrifical layer' was to remove any resin or cloth bridging over onto the electrical tape (which makes sanding later easier, with less risk to the canopy).

Once the sacrifical layer of tape was removed, i added the layers of peel ply and ensured it was pushed down using the fibreglass roller, and was totally wetted out. The use of peel ply has a couple of advantages. Firstly it leaves a thin 'floating layer' of resin over the cloth which removes any dry spots, and greatly helps to close any pinholes. Secondly, all of the 'resin blush' occurs on the outside of the peel ply and is removed when you peel it off. You are left with a surface which has the texture of the peel ply, and is ready to be primed (or in this case, sanded and shaped).