Brodhead Pietenpol Association

Original Posted By: TLC62770
William C. Beerman wrote:> > Thanks in part to some good advice from this list a few weeks ago,> I have been successful welding up prototype control horns using> both MIG and gas welding processes on mild 20 ga. sheet steel.> > However, just today we noticed that the plans supplement for the> three piece wing specifies 4130 steel to be used for the metal> brackets. This leads to the following questions:> > -Is 4130 required elsewhere in the airplane and is plain mild steel> insufficient?> -If mild steel is acceptable, then what can be done to protect and> corrosion proof these parts (especially the interior surfaces of> the control horns)?> > We are becoming more enthusiastic about the project every day, and> certainly appreciate any help!> > -Bill Beerman> (for Bill, Glenn, and Mark)The real difference is weight to strength. 4130 is aircraft steelsomewhat light for the same if not stronger. I assume you are talkinga36 flat stock. I have a book the gives the details, I'll look for ittomarrow.________________________________________________________________________________

Original Posted By: Jim Skinner
Folks,I have a Machinery's Handbook. This book has references tojust about anything having to do with metals, fabrication,and metal removal machining. It also has technicalinformation about metals, threads, tolerances, etc. I wouldhighly recommend a copy of this book to anyone who wantsthe "last word" on any of this kind of information. You canprobably get a copy used for a good price if you look ina technical bookstore that carries used books. I got minewhen I was in college, at the college bookstore.Mike________________________________________________________________________________

Original Posted By: "William C. Beerman"
I was reading through the EAA welding manual last night, in whichseveral papers discussed rustproofing the inside of 4130 tubingby coating it with raw linseed oil. Has anyone used this (or anyother) method for motor mounts or control horn interiors? How reliableis this method?Does anyone have any quantitative information on how much more corrosionresistant 4130 is than 1020?Any help is appreciated.-Bill----- Begin Included Message -----________________________________________________________________________________Date: Wed, 22 Apr 1998 13:18:50 -0400 (EDT)________________________________________________________________________________

Original Posted By: "Richard F. Rapp"
Bill,I just used the tube seal stuff that Aircraft spruce has. I think that'swhat Tony Binglas recomended. I'm not sure how good it works, especiallywith the piper strut AD's. Those struts were treated the same I think.The water acumulation must be the problem. I left my wing struts open atthe top like the plans called for. I hope it isn't a problem in thefuture. The weather has been great in Pa. Getting in lots of time.Craig________________________________________________________________________________

Original Posted By: Emelita W
I have recently cut some 4130 from the fuselage of a scrapped WW11 Cessna UC78. The fuselage was welded 4130 oiled with linseed. The interior of the tubing was just like new other than the slightly sticky film of oil. I would say that this proves the worth of the method. There were two small holes drilled at the ends of any closed tube oil poured in and then the fule rotated and allowed to drain. The holes were then plugged using small drive screws. ( the type used to hold data plates etc..)________________________________________________________________________________