Mr Charles

Mr Charles

Well Known Member
Hey fellow 4 drivers! I have been posting a thread in the general discussion area...but probably should have been posting it here...
Anyway, I have a question regarding skin replacement vs repairing a couple of very small wrinkles...and would really appreciate everyone's opinion/comments regarding this...I suppose main issue is strength? Am I compromising the strength of the plane by repairing? I do some aerobatic flight and certainly am concerned with strength issues, but not sure the wrinkle fix isn't just a purely cosmetic issue?
Would really appreciate if some would read the other thread and reply...or is there a way to reference that thread here or have it relocated here? Sorry for the forum confusion...still learning all this posting stuff!!!
Mr Charles
 
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Replies.

I am an RV4 Pilot/builder, I drive a Mitsubishi Pickup but thats by the by.

As for your wrinkles I doubt that you will get any advice based on what you have written here. You are asking for advice on a very vague description of the problem from which no one could make an accurate call.

Where are these wrinkles. (photos would really help). The other question would be what caused them, when did they appear. Wrinkles are often a sign of something being over stressed! If the wrinkles are in the wing skins you may have far bigger problems lying beneath the surface.

Post some more information and someone may be able to help.
 
When I was building my fuselage, I made a spar out of wood to go through the channel where the spar goes, and had legs on each end that raised the fuselage to a comfortable work height. The tail was supported from the tail wheel mount. Easy to make if you have a table saw and some 3/4" plywood, screws and about an hours worth of work. Solid and stable!
If a skin was wrinkled, I would just replace it. Make all the upgrades on mounts and gear now while it is all apart. Nice looking plane you have there... too bad about the oops.
 
Marilyn's RV-4 got backed too far into the hangar too many times. I fixed the wrinkled ailerons, but was never satisfied. I bought a pair of pre made RV-8 ailerons from VANs. They seem identical, except for thicker skin.
I'll be installing them when it moves to the top of my project list. Meanwhile, it flies well, but looks kinda' ruff.
It's a judgment call.
 
skin replace vs fix

Thanks for the replies so far...to Mr Arnold...sorry for confusion, the description of what happened and pics and all that are in the other thread...my question at this point is whether the skins need replaced or if I can straighten the wrinkles and fix...it is getting a new firewall, gear and engine mount (upgrade to longer gear) and a few other upgrades. But the damage to the skins seems pretty minor, and I think I can straighten ok, but didn't know if straightening will end up compromising the strength of the structure worse than drilling and replacing all the rivets to replace the side skins completely...
Mr Charles
 
Another photo

Hi

I have looked at your other thread and am sorry you suffered this.

The issue you have to consider is that the area that is damaged is without doubt the weak point on 4's, especially the early ones. Several have had damage to the lower firewall which resulted in vans making a stronger firewall weldment for the later 4's.

A number of builders have also incorporated a gusset to strenghten the area further.

Now the alloy used in building RV's does not suffer being bent back and forth well without cracking, so the issue is whether straightening will cause cracking. Without clear photos of the extent of the distortion to be corrected it is impossible to give advice.

In any event you will need a new firewall/engine mount/ longer legs/ longer brake lines anyway. The cost of replacement skins is nothing compared with the above costs.

Good look with the repair.
 
Thanks for replies

To all...thanks for the replies! I am researching addition of additional gussets. I am waiting for materials and still trying to decide whether to repair or replace skins...the damage seems so minor, but I am aware of the workability issues of the alloy. Have been talking to Ken at Tinman Technologies, and maybe I will attempt to straighten...then if have issues can then replace. Nothing to lose I think. I will post some pics of progress as I go. Once again, I really appreciate this community!
Charles
 
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