Lazair.com

Karl,

What did you use to clean up all of your tubing? I assume that you may have used alumiprep. My two-place needs a good cleaning and my tubing looks to be in about the same shape as yours was.

Dave

Hi Dave,

A lot of elbow grease!
First I used varsol and a little thinner to de-gunk the stubborn grime, next, I used Scotch Brite pads, a little polishing compound, soap and water, then applied wax to protect the metal. Keeps the metal nice and clean for a long time.

Karl

Hey Russell,

I'm with you 100% about drilling holes. These holes, however, are already in existence for rivets, so nothing new was drilled. Although the edge material for the 3/16" dia. bolts is on the minimum side of things, I have it on good authority that this was the fix. The shear strength of the bolts are many times more than the solid rivets originally installed, and nothing short of total destruction of that front plate will let that assembly rotate again. Also in that picture, you can see some original rivets that were dumped which I later changed out.
If anyone knows about other incidents, it would be some of the older more knowledgeable guys on the site (you know who you are!), and maybe they could pipe in.

Cheers,

Karl

Karl,
I did not notice that the additional bolts were in the same holes as the original rivets. Going from 1/8" to 3/16" is a small increase and I could feel comfortable doing this. This is an excellent time for me to make such a mod because there are no two parts of the fuselage mated together (not even pieces that make up the nacelles). Thanks for posting the pics.

Russell

Hi Russell,

You're welcome. Anything to help.

Karl

Thanks Karl. Thats what I have been doing except that I have been using some fine steel wool to shine things up. I guess that sometimes there is just no substitute for hard work.....bummer isn't it!

Dave

There seems to be a lot of titanium of various sizes for sale on eBay. When compared with aircraft grade aluminum 6061 is there any advantage to using titanium in strength or weight savings?

Probably would cost an arm and leg to replace the main tube, but gusettes, horns, short small diameter tubing pieces; I guess I should ask if the tools I use to work aluminum will work titanium.

This is a great read for someone who hopes to reassemble an older model Lazair, this winter. Also great photographs and thanks for taking extra effort to post the pictures.

Yup, sure is a bummer. Mind you, some things can be accelerated. Now that my engine is apart, I just got back from sand blasting the surfaces (only exterior) with a fine grade medium, and I swear it looks 10 times better than new! It gave a very nice satin-like finish to crankcase, cylinder and head. Took me all of half an hour to do it!
Next stop, thorough washing, bearing install and then complete assembly!

Karl

Titanium can be a great solution for some applications.

While converting my series II kit over to the wide gear configuration during construction, I made these F-300 and F-301 brackets out of .14" Grade 6 Titanium rather than .125" 7075-T6 (factory spec material) some had said showed fatugue cracks after extended use.

I fugured that since I had to make them anyway, I just as well do it out of Titanium so I'd never have to worry about them again.

George Curtis