Frame corrosion

[temecula50]

I am looking for a project to build and found a K5 that has been stored outside uncovered (bare frame) to the point of frame rust so bad that the powder coating has bubbled and peeled off in several areas.My concern is that there may be unseen corrosion inside the frame tubes.Any advice or ideas would be appreciated...Gerry

[jmodguy]

Walk away...

[temecula50]

Jeff, thank you for the advice.It's what I felt all along but it's great to have a voice of experience to confirm...Gerry

[avidflyer]

On the other hand, if the purchase price reflects worst case scenario, you could sand blast it to bare metal and find out what you have. If it's not that bad, you came out ahead. JImChuk

[temecula50]

Jim,Thanks for your response.I have been all over the place researching this topic and have considered your point of value.What I keep coming back to is that
these are well engineered,very light and strong air frames that are designed to sustain life at over one hundred miles and hour,withstand numerous less
than perfect landings over many years.These are not dune buggies where a frame failure would only result in an empty cooler until help shows up.I would
like to think that one stored outside uncovered in harsh weather for many years would be salvageable but I am leaning towards the "walk away"strategy
hoping to find a more suitable project.

Thanks Again guys...Gerry

[Jerrytex]

My 2 cents.....I welded tabs for the seat pan, cargo floor, etc. to my KF 5 frame. I was amazed at how fast 4130 metal starts to rust when unprotected. I sanded cleaned and epoxy primed as fast as I could to seal up the areas where I welded.

Surface rust through the powder coating is easy to deal with but any areas that have the powder coating "bubbling" off, I would be very concerned that the metal will have taking a beating from the rust. I would proceed with caution if there are multiple areas like this on this airframe.

Also it appears that most of the tubing is .035 wall thickness. Thats pretty thin, and not a whole lot of meat left if you have to sand or grind rust off.

[rogerh12]

If you go with this frame, you might as well just burn all the powder coat off, make your inspections/repairs and send it back out to be
painted. I would be amazed if it had any real corrosion that couldn't be fixed cheap enough.
Note: Rust is usually seen as the enemy, but if you use the rust as your way to bargain the price down 90%, in that sense, rust is your best friend.
Roger