Windshield bumpers

[shipljl]

Does anyone know where I can get new bumpers for the windshield? These are the tubes on the wire supports in front of the windshield tubes (see the picture). Mine are very hard and cracked.

[Hank Jarrett]

Re: Windshield bumpers

On my planes the tube was just fuel tube and the wire looked for all the world like coat hanger wire. It wasn't even very GOOD fuel line. Just rubber hose without even the nylon webbing imbedded in it.
I wouldn't have used it to carry fuel on my lawn mower, but it worked great to keep the windshield from vibrating. Note that the bumpers are NOT to support the windshield. From what I have seen they just keep the windscreen from flexing as the pulses from the prop pass. More like a shock absorber than a support. Interesting that every one I have see was welded to the steel tube after the hose was on, so no one was worried about the heat damaging the fuel tube (and it wasn't burned or damaged). Slip the fuel tube on, bend the wire around, wrap the fuel tube with a wet cloth and tack the other end of the wire down. I am betting they added the loops because it made people nervous to see the windshield move.
Hank

[Robert Lees]

Re: Windshield bumpers

<snip>..Note that the bumpers are NOT to support the windshield. From what I have seen they just keep the windscreen from flexing as the pulses from the prop pass. More like a shock absorber than a support.

I'm not sure I agree with that; the 1946 and on windscreens (sic) have quite a large flat surface that presents some significant resistance to airflow, so I think they do support it (in flight). My rubber mounts are about 1/32 or 1/64 away from the windscreen in the hangar, and in full bodily contact in flight.

But I do agree with soft rubber hose, preferably not reinforced hose, so as to be as flexible & soft as possible.

Note to Hank: Double paragraph spacing

Edit: My braces are not welded at both ends (April 1946 BC12D); see picture without the hoses put on:

[Hank Jarrett]

Re: Windshield bumpers

Yea, Mia Culpa. I am always forgetting how hard it is to read my posts when I get long winded.

I like the way your wires are attached much better. Looks much cleaner and no weld damage to the paint or potential to burn the tube. I wonder who decided to weld the second end on mine? I think I will go back to your configuration on the 45. The 41 doesn't have the wires or bumpers with the 4 piece flat panel windshield.

Hank

[Larry Lyons]

Re: Windshield bumpers

My 41 has the bumpers. However I don't know what windshield was present when she left the factory. And I don't remember if both ends are welded. Right now it has the one piece windscreen.

Larry

[Hank Jarrett]

Re: Windshield bumpers

I have a feeling you NEED the bumper with the one piece curved windshield.

There was no paperwork saying the one piece was ever actually put on my 41, it was just there (and not in great shape after the wipe down it got from a line boy with a fuel, oil and dirt coated rag. Got to remember to put flowers on his grave next time I am at that airport). The poor shape it was in was what got me started looking at the original 4 piece system. I figured since the new windshield never got logged, it wasn't actually legal to be there (if you want to get anal about it, and you know me!).

I couldn't find any photos of the bumpers on the old windshield or in any of the drawings. With as thick as the windshield is, I doubt it will flex much. I increased the windshield one thickness over original and left the windscreens (the side pieces) at 1/8". I had to work an A-6 after a bird strike and that sort of made the decision to go UP in thickness instead of down since the original material (Pyrene) and thickness wasn't available. You really can't tell it is thicker by looking at it and a little more protection means I can take a Robin now instead of a Wren.

Hank

One thing I may change on the 45 is to weld the BOTTOM of the wire only instead of the top. Doubt it makes much difference, but it just seems logical that the bottom should have been welded so the tube will have less chance of slipping off (not that it probably could).

[mike lutz]

Re: Windshield bumpers

my 1940 bc has had the one piece windsheild since the late 1940,s when my Dad owned it.He coverted it back then.It has the ring welded with the rubber bumpers on slso.They are just at the back of the windsheild and are against in flight.In past years when restoring a couple other t-crafts,I had replaced the rubber with quarter inch fuel line.I slit the fuel line and put it over the ring,then took instant adheasive(ca glue for model airplanes) and glued the slit and lined up the tubing held it for a few seconds,and was fine .One T-craft I did this too 15-18 years ago still has those same rubber tubes today,with no problems.Use some gloves of some sort so you dont glue your fingers together.This is how I have done this over the years and seems to work ok.

[Larry Lyons]

Re: Windshield bumpers

Mike good thought, I have glued rubber type hose and even made o-rings too with the instant glue. The rubber will fail first if everything is clean.

L