Vampire nose job

[Jerry Lunt]

Having separated the front section of the fuselage from the rear, I need to make a good job of re-joining them.  Fortunately, this time, I have a jig I prepared somewhat earlier to aid alignment though I've had to remove one of the filler seats which coincides with another repair.

I need to make a sleeve to fit inside which will provide the main strength of the join so I have made a wooden plug which fits loosely inside and around which I shall mould a triple layer of carbon.  The inside sections of the nose and the fuselage are slightly different, the nose being the same shape but slightly smaller overall.  I tried making a plug in one piece but screwed that up so instead, I made one long piece which would fit inside the fuselage, then cut it in half and reduced the section of one piece to fit inside the nose.  They will then be glued together for the final mould.

One question I have concerns the carbon strip you see.  I want the edges to hold together which is why it has some blue masking tape but I can't leave that there for the wrap as that part would not bond through.  Instead I should give it a squirt of 3M77 to stop the weave fraying at the edges, but will this compromise the bond of epoxy/carbon?

 

[Weysoar]

There is some clear tape you can use, usually used in the manufacture of carbon parts when defining an edge halfway across on the top layer of a layup, that would keep the edges tidy. Sorry can't remember its name, one of the suppliers should know.

[satinet]

no it doesnt

[Jerry Lunt]

2 hours ago, satinet said:

no it doesnt

I'm taking that as the answer to my query, Tom. 

Thanks.

[Jerry Lunt]

It's going to be fun getting the sleeve off the plug 

Think I will have to split it and cut out the inevitable wrinkle to get better fits into the fuselage.

[andyharrold]

cut it , thats how Tony fu does itiirc. ( it's like a spring )

should you not be laying the outside cloth at a 45 degree angle to the crack?

I will ask around my pals regarding carbon.

[Jerry Lunt]

It came off with a bit of a fight and I did 2 cuts, 1 either side of the crease seen in the top picture thus removing it.

I had to trim back part to go into the nose section to get the most in and also either side at the back so as not to cover the incidence pin holes at the front.

Then mixed sufficient Easy Composites EL2 epoxy to repair both this and my MiniVec broken in Ireland:

This 3M blue masking tape sticks rather well and so does not easily separate after the epoxy has hardened.  If I'm bothered, I may have to sand it off.  To get the smooth finish, instead of using peel ply to remove excess epoxy, I wrapped the wet carbon/epoxy with a piece of thick laminating film, smooth side down and then wound it with stretchy masking tape.  The lam film was removed before the epoxy was completely hard but the blue tape had an epoxy covering and is proving hard to remove.

For the Vamp, I then mixed in some colloidal silica to stiffen up the epoxy some, so it would not run out so easily, put the sleeve in the nose first and held it with the clamp then joined on the fuselage having painted epoxy mix into the fus and onto the sleeve, making sure it is held in the correct position on the jig.  I wrapped the joint with some insulating tape and tried inflating a party balloon inside the sleeve but that was a failure.  Still, after a couple of days hardening, it is well joined.  I will then scarf the joint to add some external carbon but need to maintain the outer dimensions so that the nose cone will fit proper 

Not sure about a 45° layup of the carbon.  I kind of think any stresses it suffers will mostly be in line with the fuselage so straight lain carbon tows does the strongest job??  It's easier to cut that way, anyhow.