Nose repair / reattachment on my glass F3B model.

[Spanner]

Having snagged a wing tip while landing on Mt Leinster at our last meeting in September the model started a ground loop which quickly converted into a wingover and the model landed vertically nose down and facing downwind. The arrival looked and sounded nasty.
Having recovered the model thankfully the only damage was an almost completely sheared off nose and a slightly damaged nose cone. (see photos)
Back at home I decided that to prevent further damage I should glue as much as possible back together with super glue. Having checked that all was straight I left overnight to cure, while I contemplated as to how I might carry out a proper repair.
What was decided was to cover the remaining holes with yellow insulating tape polish up the nose and we would be good to go.

But only to phase two!

As I did not wish to damage the fuselage behind the joint with the nose cone the repairs would have to be done internally, but how there is no way in? I decided that the servo tray would have to go, but before doing this I had to reinforce / support the damaged area from outside. This was done with a fiberglass wrap which I could later remove.I then cut away the servo tray and got clear access to complete the repair.
I ground away some of the original glass on the damaged area and filled using a mulch of chopped carbon and resin L. when this had cured I laid a strip of 50mm glass tape 200g/sqm from the rear of the wing joiner box to close to the nose, this reinforced the seam and the break. When this was set I ground down the edges so that I could get a good bond for the next layers. I added a tow of carbon along either side of the opening to replace what had been damaged in the break and this was in turn covered with a layer of glass tape on each side of the opening. These strips extended from the incidence pin location to just in front of the fuselage opening and again I ground back the edges when the resin had cured. I put two further strips diagonally over the damaged area this complete the internal work and the crutch could then be removed.
I then made a replacement servo tray which I bonded in with resin. when all was cured I ground away the damage from the outer area along the lines of the break and again laid up a mulch of Carbon Glass and resin. This got sanded back with wet and dry filled and sanded again before touching up with paint.

While the final result is not perfect but I am pleased with how it has turned out and the total weight gain was only 10g.

[billscottni]

Nice Work

[rogallo]

Hi Joe,

good to hear from you and nice to see someone at work. I started doing glass repairs a few years ago and found the thought of the work more daunting than the actual work itself. Alot I found was planning ahead and using cyano to stabilise structures before attacking , I mean repairing the model.
Your description and pictures above should encourage anyone to have a go.

Anyone else doing anything?

Ralph

[billscottni]

Ralph is right, way too many people terrified of composite work. It's fairly simple, but does need you to be organised.

Have your glass/carbon cut to the size you need. Paper templates work great for working out size/shape needed.
Use good quality barrier cream and gloves.
Check whether the brand of epoxy you are using is mixed by weight or volume and have the appropriate scales or measuring cups to hand
Loosen the caps of the bottles before putting your gloves on.
Wet the area to be covered/mended and then put the glass material into place. You may find you need 8 arms or very long fingers, again make sure you have lolly sticks or similar handy to aid getting the glass in situ. Using your brush stipple (push) resin in to the weave of your cloth, Don't over do it. If it's glossy it's probably too wet

Don't work in resin below 20 C, an old electric blanket can help keep the temp up while the resin sets.

Lots of good info here: https://www.youtube.com/@evanevshaw  or drop me a PM

[Alan_Perse]

Nice work Joe.