Iturnright

Not sure where to post this, and since this would probably relate to kit building, but I could use some tips on rebuilding crashed planes. I have a mini funtana I recieved after a serious crash, and although it is not as bad as other large plane crash 'rebuild' pictures, I could still use some tips on rebuilding.

First, should I try to glue parts that are in pieces back together, or should I just substitute new pieces for those? Second, what about tips for glueing things back into hard to reach places, I can't glue it and keep everything to stay in place. Also, should I just try and take everything apart to fix damaged pieces, or should I just try to reinforce those areas?

Any other general help would be appreciated too, I would still like to save $90 and gain some valuable building experience in the process.

Build-n-flyer-RCU

My Feedback: (4)

A beginner just arrived at the field today with a new plane that he already "crashed" into a golf cart taxiing it in his driveway and broke up the nose. His repairs were so bad that we were afraid to start the engine because the firewall was not securely attached. But we convinced him that it would be easy to repair and I brought it home to take care of it. I just finished stripping it all down. Getting rid of all the huge globs of epoxy was quite a task...

So the first rule- remember that glue is for joining wood. Globs of glue liberally applied to broken parts does not count as a repair!

Most of my planes are kit-built but some are ARFs. ARFs are usually harder to repair than kit-built planes because there are no plans. So you have to pull everything apart with some care so that you can duplicate the broken pieces if necessary.

Pull all the covering well away from all the damaged areas! You will have to repair the covering anyway and its not worth trying to work around it. Also cut away any sheeting that you need to in order to get at internal structural parts that need repair.

I try to repair pieces that are broken up but still generally attached, if possible. For external pieces you can use Tightbond (or white) glue and push and fit everything together, then clamp it all straight. When the glue is dry you can sand it all down flat with a sanding bar. You can also fill any gaps with scrap balsa and then trim and sand flat. As long as you use Tightbond or something similar this usually comes out looking pretty good after it is covered. But if you try this with CA or epoxy it will usually make a real mess that is impossible to sand out!

Sometimes it just makes sense to make new pieces out of fresh wood, especially if they are structural. Structural areas can be reinforced after repair by adding "sister" pieces and tri-stock in corners, etc. CA is fine for internal repairs to balsa. Use 30 minute epoxy for firewalls and other structural hardwood areas. Always make sure that all the old epoxy is removed before re-gluing because no glue (not even fresh epoxy) will stick properly to dried epoxy.

Once the structure is sound then add new sheeting, etc. as needed to complete the "rebuild", make sure everything is sanded smooth, and repair the covering. If you are good at covering the repair should end up just about invisible. (I avoid ARFs that are not covered in a major-brand covering material because it is hard to match).

By the way I've found that repairing even a badly damaged plane can actually take a lot less time than assembling a new ARF!

Walt

BillS

I find it important to collect every piece of wood no matter how small from the crash site. You can never tell when a pattern will be needed.

It also helps to wait a few days and think about the situation.

I tend to take as little apart as possible. Builder friends will take 10 times as much apart. There is a fine line that depends upon your building skill. One friend has become a super glue expert and his repairs are superb and quick taking almost nothing apart.

Bill

mcarleno

Agree, every little piece you can salvage. The other thing you need to be aware of, is there could be parts that have broken loose inside the aircraft. Balsa construction is designed to have a lot of little piece glued together when taken in their whole provide strength.

Example: A built up fuselage that is sheeted gets its strength from formers and stringers that are glued together. A small crack in the sheeting could be repaired with various glues; however the crack indicates that there was a lot of stress. If the former or stringers have cracked free inside, then the repair to the sheeting may not be enough to correct the problem.

I usually dis-assemble enough to inspect the inside of the aircraft prior to repairs. Another thing is glue is heavy! On a big plane this might not be an issue, but on a small plane re-building parts may be better than glueing 50 little pieces together.

Blue_Moon_

nice thread, and i totally agree.

another tips is that you can easily repair sheeting by patching the hole in the sheeting from beneath (the inside). Then carfully cut a piece that fits perfect in the hole and glue it flush with the old sheeting. fil any gaps with filler and sand. voila, you got a smooth and ready-to-cover surface [X(]

sbd-5

My Feedback: (4)

i have been building and repairing planes for clost to 40 years.i have spliced on no noses to fuelages that have broken of and disingrated in figure 9's replaced missing wing halfs after a crash etc.no repairs have ever failed.as far as gluing pieces together vs making new one.if you have the templates avalable to make new ones it would be easier and the repair would be lighter using new parts than gluing old parts back together.i usually just glue parts together to be able to draw a pattern for a new one especially for stressed areas such as firewalls bulkheads that wing mounts are glued to etc.foe splicing fuse sides and spars use skarf joints and slow drying epoxy if splice is used on both sides of fuse or wing reverse the direction of the skarf cut on the other side.