67 replies to this topic

[tim53]

So. First order of business is to remove the set screw for the latitude. It stripped my Allen wrenches, so I tried an easy out and that broke off inside the set screw. So now I’m going t file off the set screw on the inside and epoxy the hole on the outside. 

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Edited by tim53, 26 December 2022 - 05:53 PM.

[tim53]

Epoxied the hole. Waiting for it to cure so I can sand it flush. 

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[tim53]

Now the counterweights are yet another problem. It seems like I pulled about 5 years worth of belly button lint out of this one and I still can’t feel the set screw socket with an Allen wrench. 

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[tim53]

Guess I’ll get started with Emory cloth on the shat so once I get the counter with loose, I can hopefully slide them off 

[tim53]

Well that set screw isn’t going to move either. Hm. 

[apfever]

Tim,

 

Did you pick the hole in the weight clean? Did you blow out the hole with straw or hose that went all the way down?

 

I suggest some ATF and Acetone mix to fill the hole then a rubber tipped nozzle on an air gun to seal the hole and force the fluid around the set screw. You can also use a rubber tipped air nozzle to force some evapo rust type fluid around the set screws. The rust fluid should be done a few times a day to get fresh fluid in.  The main thing is to use a rubber nozzle to seal the weight hole and force in whatever fluid you try.

 

If the hole in the weight is smooth then you can use a close fitting rod (plunger), and hit it with a hammer. This shock will give more force than compressed air to get the fluid to move around the set screw. 

Edited by apfever, 26 December 2022 - 07:18 PM.

[NinePlanets]

I'm a big fan of a product called "Corrosion-X". It is a rust-eating penetrant, lubricant, and preservative. It's pricey, but in rusty situations it can sure help.

[Kasmos]

On Youtube that Project Farm guy did a test of all the common penetrating oils including a homemade one using ATF and acetone. IIRC, Liquid Wrench worked the best. It's always been my favorite but most brick and motar stores don't sell it anymore. I like it in the bottle so I can puts drops where I want it.

 

https://www.youtube....h?v=xUEob2oAKVs

 

I've seen a few but he's now racked up a ton of product test videos:

 

https://www.youtube....jectFarm/videos

[dave253]

I absolutely love seeing these old classics restored! 
Well done, tim, following the journey. 

[tim53]

Looks like this and my c14. Project will be on hold for at least a week.  We’re heading to Cosmic Acres today.  Hoping to get the mud room painted this week.  Weather isn’t looking great for astrophotography this week, but I do hope to get some sucker holes to fiddle with either Tpoint or PointXP to improve the Goto pointing on my EM500 mount.

 

Somewhere in my garage i still have a can of Craftsmen penetrating oil my dad must have bought in the 60s.  I used it as a cutting fluid when i cut the mount parts for my Springfield in 1980 or so.  Got it all over my lower arms and had a chemical burn from it that took a week to get rid of.  So I’ve been very careful of it since.  But I bet it would do a number on rusty set screws, if I can find it.

[tim53]

Still on hold.  I ordered some Corrosion X off amazon over New Years.  They said it was delivered on the 4th.  No sign of it here, so now I need to track it down or get a refund.

[YourNotSirius]

Still on hold.  I ordered some Corrosion X off amazon over New Years.  They said it was delivered on the 4th.  No sign of it here, so now I need to track it down or get a refund.

We love Corrosion-X! That is ALL that we use now! Of course, we order it directly from the company. We've never had a shipment lost. We wouldn't give Amazon one brass farthing! Never have! Never will! Loathe that company! Quite often we can do almost as well locally and even if we pay a bit extra, we have a live body with whom we can deal if the need arises. Also, we don't have to wait for shipping each way AND nothing gets stolen from our porch!

 

Two years ago we went though such a rebuild for a local school. The only difference between yours and the one we serviced is the tube counterweights. We had the optics re-coated by Spectrum Coatings in FLA. Splendid job and very quick turnaround.

 

It's a shame that you decided to give up on the set screw in the pedestal cap. That was actually an easy job. All you had to do was take a torch (a.k.a "gas wrench") to the area. Warming it and then dropping just about any type of penetrating fluid would have set things up for removal of the screw. Once warmed and with fluid in the hole some tension with an Allen wrench and a few taps with a dead blow hammer (We have both lead and brass hammers) would have broken it loose. Easy outs are a losing operation. In the many, many years we have seen them used, very few have not broken. They are too brittle to handle any real mount of torque which is why they are banned from the shop. They always create more work that they are worth. I'm certain someone will chime in saying that they are the bee's knees but, that's just luck, nothing more.

 

The most important thing when doing a restoration such as this is to have the proper tools at hand. If not, bye them. If you can't buy them then make them. We have done that on many occasions. That's why we have drawers full of extra wrenches and such. We can heat them and bend them or grind them to fit a particular job when nothing else will work. Too many projects have been mauled by not using the correct tools. Also, if you don't know how to overcome an obstacle, start asking questions. There are plenty here who can help, us included. There are very likely plenty of shops not far from your location that can offer good advice and guidance or even some of the work if it is beyond your skill level or time constraints.

 

FWIW

 

Q

[tim53]

Yeah that set screw was t the only problem. Someone had tried to move the mount in latitude by loosening the big nut/bolt and forcing it, carving a groove in the casting in the process. I’m planning On drilling and tapping a n

ew hole (or two) on the other side for the locking set screws 

 

I used to work on the Meade rg mounts at Meade in the late 70s. I have a ds16 mount to work on one of these days there are a lot of things about these old mounts that I’d improve if I were building them today. But for this one, my goal is to keep it as stock as possible - a true restoration, not a restomod. 

Edited by tim53, 07 January 2023 - 05:12 PM.

[CHASLX200]

Yeah that set screw was t the only problem. Someone had tried to move the mount in latitude by loosening the big nut/bolt and forcing it, carving a groove in the casting in the process. I’m planning On drilling and tapping a n

ew hole (or two) on the other side for the locking set screws 

 

I used to work on the Meade rg mounts at Meade in the late 70s. I have a ds16 mount to work on one of these days there are a lot of things about these old mounts that I’d improve if I were building them today. But for this one, my goal is to keep it as stock as possible - a true restoration, not a restomod. 

Seems every one of them mounts i have had had a grove dug into them. Another weak link in them kind of mounts.

[tim53]

Still on hold.  I ordered some Corrosion X off amazon over New Years.  They said it was delivered on the 4th.  No sign of it here, so now I need to track it down or get a refund.

So I ordered another bottle of Corrosion X and promised to return the first if it ever arrives...

 

...then my daughter found the first one in the yard outside the fence and under a tree.  The delivery guy must have tossed it there from the street below (we're on a hill with our street wrapped around the lot:  "Our house, in the middle of our street").  So I cancelled the new order and am keeping the first.

 

Squirted some on the set screws, but don't have time this week to work on it more intently.  We've had a lot of rain here in L.A.  It finally stopped yesterday morning, but it's coming back in the next couple days through the weekend.  We're planning to spend the long weekend at Cosmic Acres, where it's also supposed to rain, so I may not get back to this for a while.  Darn, pretty much.

[NinePlanets]

A little hint about penetrants: After application, tap the item with a block of wood or screw driver handle to set a little vibration in the rusty joint, then let it sit for 24 hours. Patience.

 

A little side-note:

My father worked at the Washington Navy Yard during WW2. He said that at times these bombed and shot-up ships would come into the yard for refitting and they would have these nasty, corroded, rusty bolts to break loose to replace the guns. He watched some of these workers pour Coca-Cola (old recipe) on the bolts and walk away for 15 minutes or so, then come back and spin the bolts right off.

 

Now, I never tried Coca-Cola for that, but it's a good story.

 

Sort of like the story about an old boy who chewed Red Man tobacco. One day he found a dessicated finger in his pouch, pulled the finger out and tossed it away, then continued with pulling out his plug of chew...

 

Which is sort of like the story about...

[clamchip]

We I was younger I rode motorcycles. Classics of course, Triumph, BSA, Bultaco, etc.

And of course I would buy broken ones and fix them up. 

The piston rings would sometimes rust solid in the steel cylinder bore.

Coca-Cola was used to unstick the piston in the cylinder on many occasions.

You remove the spark plug pour in as much as you can and leave it for a while.

If I remember correctly there's Phosphoric acid in the recipe. 

 

Robert

[65&Counting]

Hi Tim - haven't been keeping up with things (too many projects here) but you can find a replacement Hurst OEM motor for your Dec on eBay. Pricing varies but I've picked 'em up for around $50. And I mean brand spankin' new.

 

I've probably got a spare I can part with if you can't find one. Way too many Cave's here and enuf projects for 3 lifetimes.

 

Rich

[Bob W4]

Wow!!  Please keep the thread going with updates on the restoration project.  My heart melts everytime I see a classic telescope getting the TLC it deserves.

[tim53]

I hope to have a few hours today to work on loosening up some rusty set screws!  Was planning to work on it some yesterday in this wonderful weather we've had this week, but we ended up having to have our cat put down.

 

Tomorrow we're supposed to get rained on some more, so this is it!  If I can at least get the mount torn down enough to bring it in out of the weather, that'll be an accomplishment.  The OTA is inside and dry.

 

-Tim.

[NinePlanets]

Sorry about the cat. 

I have a soft spot for kitties and it breaks my heart when I lose one.

 

Anyway, good luck with the set screws and beating the rain!

[RichA]

I'm a big fan of a product called "Corrosion-X". It is a rust-eating penetrant, lubricant, and preservative. It's pricey, but in rusty situations it can sure help.

Better to sandblast the pier and counterweights.

[YourNotSirius]

Note: For such soft metal as aluminum housings and such I prefer to use soda blasting. Also, crushed walnut shells work well. Sand blasting is too rough on soft metal. For steel it is fine but, not for aluminum and such. For what you have here I would just use paint stripper, a brass wire brush and one can of elbow grease. LOL

 

The YT program "Project Farm" is really well done. However, he never gave Corrosion-X a try and I will stack that up against anything he has tested.

 

FWIW

 

Q

[tim53]

I also use a brass bristle brush and, if necessary, paint stripper.  I find that most of the time with these old mounts that were never primed, the original paint comes off easily:  in sheets, if it's not oxidized; and in clouds of dust, if it is.

 

I've used evaporust for rust removal before, but not for taking stubborn rusty set screws out.  

 

Saturday, I had planned to get a propane bottle and use my torch to apply heat to errant fasteners (soaking in corrosion-x for weeks now).  But I must have dropped the torch at some point, because the plastic halves were partly separated and the igniter wouldn't work.  So I pried it apart, breaking a few remaining plastic tabs in the process.  Then, I just went to Home Despot and bought a new torch.  Then got home and realized it doesn't have an igniter.  Okay, so I would use a bbq lighter.  Only slight breezes kept blowing it out.  So I figured I'd work on it yesterday, only it was cold and raining.  So now it's monday and I have work to do!

 

-Tim.

[cavedweller]

... and one can of elbow grease. LOL

 

 

I prefer my elbow grease (Voltaren) from a tube.