Hey guys,
I'm a newbie here and just started tearing down a champ we picked up back in Jan. Just when I thought things were going pretty good with the project I got slapped in the face with some reality today. Me and a friend from my A & P class were taking the wood off of the fuselage getting ready to sandblast it and he noticed some rust stains in the tubing where the horz. stab cluster is, so I took a screwdriver and punched right through it. After seeing that we started to investigate more and found 2 more bad spots on the lower tube near the tail wheel. So it looks like I'll be doing some reading and welding pretty soon. Any advice/suggestions on making these repairs? I'm going to try to get some pics of it posted here in the next day or so.
Johnny
Champ restoration
Re: Champ restoration
Johm,
I fiddled around with trying to patch something at the back end, mostly to try to correct someone's old cobbles, and finally wound up running new lower tubing all the way from the 'fish mouth" (where the tubing changes sizes) to tailwheel post on both sides. It's not as hard as it looks to build some kind of a jig and weld in new tubing. Although, if the rest of the lower tubing is good it might not be necessary. I can't speak to the horizontal stabilizer attach tubing but it should be 'fixable'. Also, check the right front vertical tube at the landing gear for being bent. It's fairly common from hard landings.
Mike
I fiddled around with trying to patch something at the back end, mostly to try to correct someone's old cobbles, and finally wound up running new lower tubing all the way from the 'fish mouth" (where the tubing changes sizes) to tailwheel post on both sides. It's not as hard as it looks to build some kind of a jig and weld in new tubing. Although, if the rest of the lower tubing is good it might not be necessary. I can't speak to the horizontal stabilizer attach tubing but it should be 'fixable'. Also, check the right front vertical tube at the landing gear for being bent. It's fairly common from hard landings.
Mike
Re: Champ restoration
Sorry for the crappy photos, My cell doesn't take the best pics.
Re: Champ restoration
Johnny,
Sorry to say that this is the typical areas where the Chief/Champ's get rust. Take a automatic center punch and go up and down the tubing especially in the rear sections.
At least you found it before there was an accident.
Joe A
Sorry to say that this is the typical areas where the Chief/Champ's get rust. Take a automatic center punch and go up and down the tubing especially in the rear sections.
At least you found it before there was an accident.
Joe A
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FlyingWrench
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Re: Champ restoration
First of all relax, good thing you found it. Sounds like you are in A&P school so you have some resources to ask. Evaluate the whole fuselage, then formulate a repair plan. One step at a time. A lot of things have to happen before you light the torch- like designing the repair, jigging, getting the proper tubing etc.
Can you do the welding in school as a project? It would be great to do a live repair on a real airplane when you are in school. It drives home what you are learning.
This is why you are in the business, to make sure airplanes are airworthy. It is one thing to be on the giving end of bad repair news and it is quite another to be receiving end. It will serve you well to experience both sides.
My .02.
David
Can you do the welding in school as a project? It would be great to do a live repair on a real airplane when you are in school. It drives home what you are learning.
This is why you are in the business, to make sure airplanes are airworthy. It is one thing to be on the giving end of bad repair news and it is quite another to be receiving end. It will serve you well to experience both sides.
My .02.
David
Re: Champ restoration
I was apprehensive at first on replacing tubing but using a air tool with a 'whiz wheel' it's pretty easy to cut out the bad tubes at the weld and weld new ones in. It looks like you have some pretty intensive rusting on your air frame. Be careful of tube thicknesses as .035 was common but there were a few places that used different wall thicknesses for strength. A good time before welding to check fuselage alignment by measuring from a forward common point back to the tail post and from the front wing attach center hole to the strut attach center of the hole. It should be 48 and one half inch.
MikeB
MikeB
Re: Champ restoration
48 1/2 inches? Are you sure about that? Seems to me (without actually measuring) that from the forward wing attach point to the tail post is a lot longer than that??
Mike
Mike
Re: Champ restoration
Hmmm! Maybe I didn't make it clear enough. Your measure from the center hole of the front wing attach bolt hole to the (lift) strut attach bolt hole center. That measurement should be 48 1/2" which is often off because the right front vertical tube at the landing gear is bent. Don't ask me how I know as I found out too late 
. If the tube isn't replaced the usual way to cure the problem is to install a (legal bythe way) split tube over the old tube but that only cures the symptom and not the real problem, although it's certainly strong enough. Basically it can affect the door fit if nothing else. I often wondered why the doors fit so poorly on some of the Champs. The left side is braced a bit better so not so usual there.
The other measurement I was talking about is to measure from a common point in the front which is usually the strut attach plate and back to the tail post. I don't know what you'd be allowed here but too much could certainly make things interesting with the ground handling. I think this usually get off if tubing is replaced at the tail section and/or heavy welding on one side or the other which pulls things out of place. I suppose the distance from the landing gear attach to the rear is another factor. I'm a rookie but I'm still learning (I hope)
.
I think there's very few Champs or Chiefs, Taylorcrafts, J-3's etc. that haven't experienced some banging around and gear repair over the past 60+ years. Although I'm quite sure I've never bounced one on landing
.
Other Mike..
. If the tube isn't replaced the usual way to cure the problem is to install a (legal bythe way) split tube over the old tube but that only cures the symptom and not the real problem, although it's certainly strong enough. Basically it can affect the door fit if nothing else. I often wondered why the doors fit so poorly on some of the Champs. The left side is braced a bit better so not so usual there.The other measurement I was talking about is to measure from a common point in the front which is usually the strut attach plate and back to the tail post. I don't know what you'd be allowed here but too much could certainly make things interesting with the ground handling. I think this usually get off if tubing is replaced at the tail section and/or heavy welding on one side or the other which pulls things out of place. I suppose the distance from the landing gear attach to the rear is another factor. I'm a rookie but I'm still learning (I hope)
.I think there's very few Champs or Chiefs, Taylorcrafts, J-3's etc. that haven't experienced some banging around and gear repair over the past 60+ years. Although I'm quite sure I've never bounced one on landing
.Other Mike..
Re: Champ restoration
First of all I'd like to thank you guys for your advice. Today both of my instructors and I looked at it and we all came to the conclusion that I need to sand blast it first, then go on and do the measurements and center punch the hell out of it again, make the repairs and get a epoxy primer on it
As far as repairs with what we know is wrong right now, one of the instructors mentioned a inner sleeve and a new section back to the tail post for the lower. For the upper we kicked it around about making a outer sleeve. I took a center punch to the cluster while we were looking at it and nothing blew through, then one of the instructors tapped that area and the only dull sound came from where the whole is.
Luckily all the work I'm doing to this old girl is being worked in with all my projects that relate to it. The bad thing is we don't get a heck of a lot of time to work on things so I might be bringing it home so I can spend some more time on it.
After I get the major repairs done I have to make some of those u brackets the formers are fastened through and weld them in place. Is there anything special I need to do for those? they look like a pretty simple thing to make and weld on.
Thanks again
Johnny
As far as repairs with what we know is wrong right now, one of the instructors mentioned a inner sleeve and a new section back to the tail post for the lower. For the upper we kicked it around about making a outer sleeve. I took a center punch to the cluster while we were looking at it and nothing blew through, then one of the instructors tapped that area and the only dull sound came from where the whole is.
Luckily all the work I'm doing to this old girl is being worked in with all my projects that relate to it. The bad thing is we don't get a heck of a lot of time to work on things so I might be bringing it home so I can spend some more time on it.
After I get the major repairs done I have to make some of those u brackets the formers are fastened through and weld them in place. Is there anything special I need to do for those? they look like a pretty simple thing to make and weld on.
Thanks again
Johnny
Re: Champ restoration
Johnny,
Where are you located? Reason I am asking is that very few fuselages are "true" these days and Brian Safran who is in the Indiana/Ohio area has Bill Pancake's old Champ fuselage jig. He lets anyone use it for FREE as long as his welder is not involved.
In other words you can put the fuselage in the jig, check it for being true and "adjust" as needed and there is no charge unless he or his welder gets involved in repairs. If you are not too far, sure would be nice to make sure that the fuselage is true while you are doing this, especially with major repairs in the future.
Joe A
Where are you located? Reason I am asking is that very few fuselages are "true" these days and Brian Safran who is in the Indiana/Ohio area has Bill Pancake's old Champ fuselage jig. He lets anyone use it for FREE as long as his welder is not involved.
In other words you can put the fuselage in the jig, check it for being true and "adjust" as needed and there is no charge unless he or his welder gets involved in repairs. If you are not too far, sure would be nice to make sure that the fuselage is true while you are doing this, especially with major repairs in the future.
Joe A
Re: Champ restoration
Joe-
He sent me a pm and told me about it yesterday, I just read it this morning. I'm located in Iowa so it is a option. My biggest problem would be the time to get it out there with work and school. It would be nice to have a jig when we go cutting and welding in the new parts. I know back in the 50's it had the left gear wiped out so I agree that the odds are it's not the way it's suppose to be.
Thanks
Johnny
He sent me a pm and told me about it yesterday, I just read it this morning. I'm located in Iowa so it is a option. My biggest problem would be the time to get it out there with work and school. It would be nice to have a jig when we go cutting and welding in the new parts. I know back in the 50's it had the left gear wiped out so I agree that the odds are it's not the way it's suppose to be.
Thanks
Johnny
Re: Champ restoration
Well I went out on lunch and measured the front wing/spar attachment holes like you guys told me to and after measuring each side 3 times I came up with 48 9/16 on both sides from center to center. Could this be right or is something jacked up?
Re: Champ restoration
I don't know that being a bit long is a problem as that could come from manufacturing "tolerance" if there is such a thing. If it's the same on both sides I wouldn't worry too much about it. The problem is when the right front vertical tube gets bent from hard landings, then things get short. Another thought: try your door in the opening and see how it fits. Most of these old airframes have a lot of 'warts" (like all of us over 60) It just depends what's tolerable or not in my humble opinon.
Mike
Mike
Re: Champ restoration
Who has the better wood parts? Wag or rainbow?