Fiberglass Repair

[Alan_Perse]

Hi all.

I just wanted peoples views on how to repair a fiberglass fuselage. My DHLG fuselage to be more exact. I was trying to fly it over the weekend and it had a bit of a hard landing. The wing seat is cracked in multiple places. See the picture below.
It should be noted that some of the cracks were already there from a previous bad landing and I repaired them by putting some carbon fiber reinforcement inside the fuselage. But now even those cracks are even bigger. I can't put any more reinforcement inside the fuselage. It's just to awkward. Putting in the previous carbon reinforcement was difficult enough.
What do you think I should do?
   

[Fred]

Hey Alan,

If that was me, press the fuselage to reduce the width of the cracks, and CA.
I would still put some FG or Carbone on the inside (you will need to make your own tool for that, a roller with a kind of a flat U shape if you see what I mean  :?:
That will allow you to apply the carbone correctly and easily inside the fuselage.

You can always put some carbone cloth outside on the wing saddle. Just respect the original wing incidence, and that's it (sand the gelcoat a bit before applying the cloth with resine...)

Hope this helps.

[Alan_Perse]

Thanks for the reply Fred.

I will compress the cracks and put CA in them as you said.

I would still put some FG or Carbone on the inside (you will need to make your own tool for that, a roller with a kind of a flat U shape if you see what I mean  :?:

I understand what you mean. The problem is that there not much more space for carbon or fiberglass reinforcement inside the fuselage. There are lots of things in the way such as T-nuts for the wing bolts etc. The reinforcement I put in before was in a area where there was nothing in the way. But now the cracks have spread. I guess I will have to put some reinforcement on the outside. It won't be pretty but DHGL gliders don't look that pretty anyway   .
The next question is will fiberglass be enough or will I have to use carbon-fiber.

[billscottni]

Get some carbon tape or cloth and after you've CA'ed as Fred said, put a layer across the entire wing seat making sure it maintains the incidence. As Fred said you need to sand the gloss off the gelcoat first to get good adhesion

[Alan_Perse]

Thanks Bill and Fred. I'll give it a go.
Flying a DHLG is not as easy as it looks.

[rogallo]

Alan,
    carbon stitching is the answer here methinks. CA back all the cracks, get your dremel motor tool with glass reinforced cutting disk. Cut slots with the disk at right angle to the crack but not so deep that you cut through the fuse. Then get carbon tow and lay it in the well you have just created. then more CA. sand, prime and repaint.

If only it was that easy  

 :!:  :!:

Just a thought!

Ralph

[Alan_Perse]

Thanks Ralph. I'll have a think about it. I'll defiantly CA the cracks though.