I just mentioned WD40 because I've seen a lot of folks in the club use it that way and for that purpose and its usually sitting around.

This is actually a very helpful topic, but provides another reason why investing in one's own launch rail might be a good idea if one is looking for optimal performance.

Its interesting to note that WD40 (Water Displacement 40 - It took 40 tries for the inventor, Norm Larson, to get the right chemical formulation) had its roots in 1953 as the Rocket Chemical Company and was 1st used to prevent corrosion on the Atlas Missile. "Rocket WD40" was put on the store shelves in 1958 and became so popular that the company changed its corporate name to WD40 in 1969.

Love the stuff, used it all over the screws in our F4's on the USS Coral Sea during Vietnamm 1967-1968, but hate it when used outside as it is a major attractant of dirt. The carrier had plenty, but the prairie has more.

Once sprayed on a rail, the inside of the T-slot, the surface that slides on the buttons, will be permantantly coated with abrasive grunge as it is not accessible by a rag to wipe off. My reccomendation is to only use an evaporitive solvent like Denatured Alcohal, as it will wash away WD40 and other sticky messes. A small bottle brush with non-metallic fibers could be used to clean the inside of the T-slot. Metal wire brushes should be banned from ever touching the rails as they will break through the thin layer of anodizing.

We can do an experiment: take various sprays like WD40, silicone dry lube and others and spray a small spot on our cars, then drive it around. It won't take long before before the spot will blacken. The best rail is a dry clean rail to eliminate stiction and abrasion.

My favorite use of WD40 is to remove the gummy adhesive from sticky-back labels.

This is completely off topic, but given the industry you work in Mike, I wonder if you could comment on this.

A while back, it was reported that ALL the hard disk drives in the ISS essentially seized up within hours of one another and have since been replaced with solid state "hard drives" meaning flash or similar Ram disks. Is this an issue with lubricants or bearings in zero-gee? The drives were all about 6 months old as far as in-flight use was concerned.

Warren

I just mentioned WD40 because I've seen a lot of folks in the club use it that way and for that purpose and its usually sitting around.

W

And, that's what we use at every bi-yearly cleaning party. This really IS a good thread, guys. Warren, 10-24/32 screws are fine to hold rail buttons on. I just said what I said earlier since most people use 1/4-20's. As JW mentioned, probably just over-building. This is really good information you are all providing.

I've also been happy with some black powder cleaner I picked up at the store where I got my Pyrodex. I think it's water soluble, but it made cleaning out the inside of my rocket a snap. I wonder if it would work as well on AP residue?

For what its worth, BOY SCOUT water works pretty well at cleaning up the AP residue on rails and in motor cases but you need to re-grease afterwards, or use the stuff we used in the Colorado Army National Guard - CLP (Cleans, Lubes, Protects).

IMHO I bet that the stuff I and many other folks have used as a release agent for casting propellant would be fantastic. It makes things very slick and non-sticky. For cleaning again stuff like wd40 works great. But out on the field a modified spray that would enhance the rail to have way less friction would be better.

Mike,

Your comments about stiction highlight a belief of mine when it comes to lubricating towers for minimum diameter flights. I've see lot's of discussion about the best lube for the tower on high altitude flights, but I've always been a fan of dry towers. It seems that the WD40 would actually slow the rocket and you're better off having a dry surface, or maybe even use powdered graphite as a lube. You want the rocket to immediatly "bounch" off the hardest surface possible rather than grind into it.

As you point out the lateral forces are EXTREMELY small compared to the forward forces.

(Apologies for yet another diversion on Warren's swap-meet thread)

This is on/off the subject. I would be more than happy to do
a cleaning of the rods and rails during a three day launch. Like
mid Saturday. Not all at one time, just one every so often.

I know I have had to grab some pretty nasty rails during
a three day launch. One of My rockets still have my prints
all over it.

When it is decided what to use. Let Me know.

When I am not flying I am out taking pictures, so I am right there.

Have you ever tried Brakleen? The chlorinated stuff works *way* better. I've fired a motor, let it sit in the sun for 2 months, then cleaned it with that and it is as shiny as new.

Edward

If I recall correctly, Brakleen is a halogenated solvent and as such is a major source of ozone destruction in the stratosphere and upper altitudes. They do not break down for hundreds of years. Awesome for cleaning guns too.

Warren

You'd think if it were as bad as CFC's they'd ban them. They still sell it in up to 55 gallon barrels 🙂

Edward

This is completely off topic, but given the industry you work in Mike, I wonder if you could comment on this.

A while back, it was reported that ALL the hard disk drives in the ISS essentially seized up within hours of one another and have since been replaced with solid state "hard drives" meaning flash or similar Ram disks. Is this an issue with lubricants or bearings in zero-gee? The drives were all about 6 months old as far as in-flight use was concerned.

Warren

I haven't been tuned into actual disk drive manufacturing for quite a while, as I've been relegated to using HDD manufacturer's drive in our arrays. STK and then Sun doesn't do much with NASA although there is a large DARPA presence. One thing I had to do (back in 1985) was convert the grease in the bearings to a self-channeling non-outgassing (I think lithium based) grease and any parts made with any sort of silicone mold release was not allowed. As far as i know laptops with HDD are still being sent up and used on the shuttle. They are always in an area that has atmospheric pressure, unless for some reason they are caught outside in a vacuum where all the problems start. You need air pressure to fly the heads. 😯 It only makes sense to switch to SSD since they are getting cheaper, don't have heads to fly, and do not add rotational moments to the space station. The best mechanism is no mechanism. I work with some ex-maxtor people. I'll ask if they know anything. It was too long ago for me to be a reliable source.

This was some random comment I read on the ARocket list where it was reported that several drives all failed in quick succession. There was discussion of the impact of zero-g on the bearings and/or lubricant.

W

Warren,

I've been in disk and tape drives for about 18 years now. Zero gee should have zero effect on any of these storage devices. As Mike stated, you do need air, though. The head media spacing is a balance between the aerodynamic "flying" of the head over the media and a good old fashioned bent sheetmetal spring suspension. Outgassing of bearing lubricants and media lubricants would also be only affected by vacuum and/or sitting unpowered for too long. I'm a firm believer in leaving them spinning. Any I've lost have been on power up.

As for them losing a whole set at once, bad lots happen and do get shipped occasionally. Those usually die in infancy. I've got drives that are >20yrs old that still run, and I've had some die on first spinup.

Ken

I know I have had to grab some pretty nasty rails during
a three day launch. One of My rockets still have my prints
all over it.

This has happened to me also, please remember whatever lubricate you choose it only works on the move pieces or contact points. So don't spray the whole rail and forget to wipe the extra off. My favorite lubricate would be something with Teflon in it. It dries quickly, doesn't attract lots of extra dust, and leaves a slick surface. Unfortunately like many things it may not be good for you or the Earth in the long run, but what is.

Ron