ReefBlueCoupe

Over the weekend I had an unfortunate incident during which a nosed into the runway at a 45 degree angle after a sharp turn following the engine dying, and the wind dying as well. It was from about 10 feet, almost no forward speed, but had sufficient force to break the engine/firewall away from the plane, as well as part of the balsa underneath the plane. Nothing splintered and it was all pretty easy to epoxy back together as it fit like a puzzle, but being new to flying/repairing RC planes, there's a little bit of doubt in me of whether it will hold as good as it did from the factory.

I did some common sense things such as epoxy every place wood meets wood, as well as epoxy the inside joints and reinforce with scrap wood The epoxy dried rock hard (6 minute epoxy) and you can hold the plane horizontal by the engine mount, and vertically with it, jerk it up and down and side to side, and there is no flex or give, but I just want to know what people's repair experiences are. I know some things can seem fine on the ground but once subjected to the force of a snap maneuver it could fail.

Who thought their repaired plane was good to go only to have bad things happen once it was back in the air

RC MANIAC119

My Feedback: (14)

That repair you made should be fine. Next time however, I would re-enforce that firewall with some 1/2 inch tri-stock, before the epoxy went on.

Good luck with the next flight...........

Flying freak

Should hold, next time use a stronger epoxy somthin like 30 minute.....

Jester241

That sounds about like what I did last weekend. I just lawn darted my P-51 into the ground and it was hopeless to put that firewall back together. I ended up sawing the whole front end off a half inch back all the way around and epoxying a new firewall on top and reinforced in a tad. I still had come tri-stock left along the sides to help too. Yours sound like it should be ok,but you should have used 30 min epoxy(soaks into the wood longer,and dries harder IMO)....no big deal though,6 min will work though as long as you put enough on quickly enough. I always have a hard time getting everything in place and epoxied well in that short of time.

Steve Steinbring

Your repair seems to be just fine!

Realize that most all epoxies exceed the fiber strengths of most soft woods. If your bonding woods like balsa, pine, poplar, fur,and a few others the fiber strength would be below the strength of a quick set epoxy. The shear strength of a quick set epoxy is generally around 2000PSI. Soft woods like pine or fur generally have a fiber strength of around 1600psi.

When bonding non porous materials and harder woods like oak or ash it best to use a longer set epoxy. Thats because the slower epoxy will penetrate the substrate better giving a stronger bond. Its very important to use proper surface preparation have the joint area clean, free of dust, oil, greases, and other contaminates.

Always use the strongest joint design possible, butt joints for example are very weak. Proper reinforcement in critical areas is always a plus, in most cases its not the adhesive that fails.

ReefBlueCoupe

Thanks for the info.

I would have used 30 minute epoxy, but all I had was 6 and I was anxious to see if I could repair this one or if I was going to have to buy a new fuselage and have it here by Friday so I could fly Saturday.. I couldn't wait for the hobby store to open to get 30.. Home Depot and Wal Mart didn't have any. I was able to use it by mixing smaller batches more frequently.

I do need to buy some though so I'll snag some the next time I go.

It is my first plane.. hopefully I'll learn most of my lessons on it and keep future planes repair free!

ReefBlueCoupe

Well I've flown it a bunch since then and it's held up great.