Brodhead Pietenpol Association

Original Posted By: "Gary McNeel, Jr."
Gene,We have been over this before in the archives. This is from the archives:I will quote from Performance Welding by Richard Finch who is an expert inwelding, is in the aerospace industry, and wrote the parts of AC 43-1Brelating to welding. He says, and I quote without permission:"Brazing SteelAlways avoid brazing 4130 steel. The reason to not braze chromemoly isthat the steel has a definite grain structure that actually opens up atmedium red brazing temperatures. When brazing alloy is melted onto thesteel surface, it flows easily into the many small cracks and crevices inthe chromemoly steeel. Then as the braze joint cools, the brass will notcompress and it forces MAJOR cracks to form in the 4130 steel. Often, abrazed 4130 steel part will crack completely in two before your eyes as itcools.Mild steel (1020, 1025, and so on) is ready made forbrazing..........Brazing, when done correctly, can last as long as anyother metal-joining method. And it can be as strong as fusion welding whenit is done correctly."________________________________________________________________________________Date: Wed, 25 Jun 2003 12:44:25 -0400

Original Posted By: "Craigo"
wrote: Then as the braze joint cools,> the brass will not> compress and it forces MAJOR cracks to form in the4130> steel. I used to own and race Formula Ford cars, made inEngland with BRAZED joints. True, they weresilicon-bronze brazed, BUT: Whilst rounding turn 9onto the straight, the right rear upright let go,putting me into the wall at about 135. Major damage toboth the car and to me. Why did it let go? A majorcrack in the brazed joint at the top of the upright! Convinced me to always use welded joints!!!!CraigLake Worth, FLBakeng Duce NX96CWPeoplePC: It's for people. And it's just smart. http://www.peoplepc.com ________________________________________________________________________________

Original Posted By: "w b evans"
wrote: Then as the braze joint cools,> the brass will not> compress and it forces MAJOR cracks to form in the4130> steel. I used to own and race Formula Ford cars, made inEngland with BRAZED joints. True, they weresilicon-bronze brazed, BUT: Whilst rounding turn 9onto the straight, the right rear upright let go,putting me into the wall at about 135. Major damage toboth the car and to me. Why did it let go? A majorcrack in the brazed joint at the top of the upright! Convinced me to always use welded joints!!!!CraigLake Worth, FLBakeng Duce NX96CWPeoplePC: It's for people. And it's just smart. http://www.peoplepc.com ________________________________________________________________________________

Original Posted By: "Michael D Cuy"
Mike,I've balanced both my U/L blades, and my Sensinich this way. Its fairlyeasy and effective...For the shaft that you will pivot on I used a chainsaw file. Real cheap,straight, and vertually wont bend. Then I made two circles out of 1/8" (orcould use 1/4") aircraft ply. Drill clean hole in two pieces of ply tomatch the size of the file. Then bolt them together using that hole, andput in the lathe to turn down the OD to just be able to push into the prophole snugly with your fingers.Now ready to balance. You can use two parallel pieces of steel, or I justused the vise jaws.Make sure you check out the setup this way,,,1 set in jaws looking at front of prop, and make note of which tip drops.2 rotate prop so now looking at rear of prop (left and right tip still atsame ends) take note of heavy end3 look at rear but put right tip on left and vice versa4 lok at front with tips same as #3note; you're just checking 4 different setups to make sure any error is notbrought on by the vise. The cool thing is, is you can take a piece of paper about 2" x 3" foldedin a "V" and hook it on a tip and see it fall. Thats how sensitive it is. Try all tips in all configurations. When you are sure of the setup, andthe prop is in the condition that you want, you can simply brush on anotherswipe of urithane on the light blade till it balances. Have to touchupwhen dry cause the solvents in the varnish weigh something and theyevaporate off.We have talked about repairing chips and dings in a wooden prop? Usingsuper glue and baking soda. It's an amazing process..easy, looks great, anddoesn't let go.If anyone wants to rehear it let me know.walt evansNX140DL----- Original Message -----