mount small to large shaft

Brake-Kleen isn't supposed to leave a residue. I use it for final cleaning of bearings after gross cleaning with varsol and acetone, which do leave residues.

Reply to
Don Foreman
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Finely thread the pulley ID and the shaft OD. Might require disassembling the motor.

Reply to
Richard J Kinch

It hope it will be useful to you sometime, Michael. Epoxy can be fairly complicated, especially when you get into the elevated-temperature-cure industrial products that we never see on the regular markets. They can have tensile and sheer strength running 2.5X stronger than anything we can buy in small quantities. Epoxy is great stuff but you really have to understand its properties when you use it for hefty loads. For example, the stronger it is in shear, the weaker it *may* be in peel.

I don't know where this scratch-in idea started, but I think I know where it first appeared in print: in the Gougeon Brothers' first book, published in the early '70s. (The Gougeons were the originators of the WEST epoxy system.) They used it to fasten stainless deck hardware to their boats.

Since those guys are highly respected empiricists -- they actually test and try their ideas before talking about them -- it caught on in the boating community. Then it started to show up in metalworking, with some of my writing in the late '70s a possible contributor. d8-)

Anyway, I've used it many times, and I've done some of my own testing (with pry bars and hammers ), and I'm sold on it. FWIW, I've gotten mixed results with copper alloys, so I don't know about using it on them. Sometimes yes, sometimes no.

-- Ed Huntress

Reply to
Ed Huntress

That's interesting. The thread-locking Loctite products are mostly anaerobic acrylic adhesives. I wouldn't know if that's a characteristic of acrylics in general or not.

Epoxies usually have pretty good fatigue properties, which is evidenced by the fact that they glue a lot of aluminum aircraft skins with them. Those rivet-bonded wings do NOT derive any significant strength from the rivets. That's not why the rivets are there. The strength comes from the epoxy, and aircraft wings are always a potential fatigue site.

-- Ed Huntress

Reply to
Ed Huntress

This gets my vote, too. If (unlikely) the hub has enough extension, one can also pipe-thread it with a die, and cinch with a pipe-threaded nut (to make a kind of collet). The taper on pipe threads makes a lot of circular wedging operations do-able.

Reply to
whit3rd

Or run the pipe tap into the hub and bore out a reducer bushing to fit the shaft, then slit the threaded end to allow it to compress. Iron pipe fittings aren't always threaded very accurately, so I center a machined brass one in the lathe and use it to center the threads of iron pipe and fittings. Steel hydraulic fittings turned from bar stock may be concentric enough inside and out.

jsw

Reply to
Jim Wilkins

Just clean pulley and shaft and then use Loctite 603 or a close relative. I use it with no problems both on pulleys and to drive 5" dia 4340 blanks on

1/2" drill rod arbour. Works well enough to take .050" cuts with nice blue chips :-)

Mark Rand RTFM

Reply to
Mark Rand

I did a lot of reading and experimentation with epoxy a couple of years back when I was trying to glue stones to one another. I got pretty decent results - until you put the stone structure outside in the sun. Epoxy does not like that!

Now I am experimenting with gluing the sundial faces to the armature. The obvious way to attach the two is either welding or brazing, but any heat application to a finished face can play havoc with it. I tried screwing the two together, but there is only so many 10-32 threads you can get into a blind hole drilled at the back of a 5 mm face, let alone the sweaty feeling when drilling the blind hole into a finished face hoping that you do not break through.

I had a fairly decent result with JBWeld but he key was the area of adhesion which I made purposely quite large. That is something I would like to change. I did a few experiments with different shapes of the bonded surfaces (milling little pockets etc.) but the strength has been inferior so far.

What I noticed almost without exception is that when the bond breaks the epoxy separates almost totally from one of the surfaces whilst still adhering to the other. There is almost never a break "through the middle" of the bond. I make it a rule to prepare both surfaces the same way but this suggests to me that I am failing on one of them (both are steel, BTW). The scratch-in method may be the answer.

Reply to
Michael Koblic

It may be. The failure mode you're describing sounds like a basic adhesion problem, due either to tying to bond to an oxide layer or to contamination of the surface.

It's not unusual for epoxy to let go like that, and the stronger the epoxy, the more likely it is. When there is a peel or cleavage load on the joint and a tiny spot at an edge has poor adhesion, the peel will start there. Then it peels catastrophically. That's the exact type of failure that rivet-bonding is intended to prevent in aircraft skins. The rivets prevent the initial lifting of an edge.

Epoxies modified with elastomers are intended to reduce that peel weakness. Most epoxy products sold at retail have some degree of resistance to it (and a somewhat lower shear and tensile strength as a result), but most epoxies are more vulnerable to peel failure than some other adhesives.

So it's important to have a really clean surface to eliminate the weak spots near the edges of the bond. On many metals, the degree of cleanliness needed to get the best performance disappears within seconds of the metal's exposure to air. Preventing that contact with air is what scratching-in is all about.

Good luck.

-- Ed Huntress

Reply to
Ed Huntress

On Jul 23, 10:26=A0pm, "Michael Koblic" wrote: [attach thin plate?]

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Reply to
Jim Wilkins

So when I intuitively applied a layer of epoxy to a flat armature base and then also screwed it down with 10-32 screws (each with about 1.5 threads) I seem to have followed a sound principle! Great minds and all that...

Another way (again, intuition!) I tried to prevent a peel was to embed a stud into a shallow milled cup at the back of the face. That did not work but I wonder if that was partly because there was a lot of play around the

0.495" diamter stud in the 1/2" (nominal) milled hole.

I have got a 1/2" reamer on order. I wonder if a tighter fit in a hole will restrict the tendency to peel better (the hole is only about 0.1" deep).

I have another trial under way right now - same hole pocket as above (the reamer has not arrived yet) but tried the scratch-in method (difficult to do in a 1/2" hole) and instead of JBWeld using a West System epoxy. Note to self: Even the minimum amount mixed up in a 30 degree weather can produce impressive amount of smoke and bubbling very quickly.

That is the main knock against the West: You have to mix up a minimum amount which for me is usually many times what I need. I have taken to using the rest up in making knobs for my Taig etc. but today the speed of the reaction rather overtook me.

Acetone and Windex usually does it for me. I have used a more aggressive degreaser on occasions instead of Windex but the rust would form in front of my eyes.

I shall report tomorrow.

Reply to
Michael Koblic

Reply to
Michael Koblic

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Don't have one, don't know how well they work, studs aren't rustproof, but it's a start. Has anyone tried them with other hardware such as stainless steel flathead screws?

jsw

Reply to
Jim Wilkins

That one could be used for structural purposes.

Wouldn't waste the effort if this is structural - Those studs are meant to be a short-term weld to grab onto a chunk of fender and pull out the dent with a slap-hammer. (Which is included, even!) Then when you have the dent pulled out the stud welds are supposed to release fairly easily by bending so you can clean up the fender and do your prep and paint.

And I wouldn't count on the tool to live long - most Harbor Freight stuff is Light Duty and will live okay for an occasional home project. If you plan to use it all day, every day, for pay - buy two, and carry them both. So when one dies, you have the other one to finish out the day, long enough to go buy a new spare.

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Reply to
Bruce L. Bergman

OK, as far as I can determine there have to be studs of definite shape to work with this (certainly with the HF one!). One would hope that one could weld other fasteners this way to flat pieces, e.g. short lengths of threaded rod.

I wonder: Could one improvise this method? I guess a few Leyden jars would fill the bedroom...

Reply to
Michael Koblic

The Rig my Father's firm used in the mid '70s had a 1 Farad 80V capacitor bank and mercury wetted contactors. Fairly serious.

Mark Rand RTFM

Reply to
Mark Rand

On Wed, 22 Jul 2009 23:49:59 -0500, the infamous Don Foreman scrawled the following:

Yeah, I've used lacquer thinner, Brake-Kleen, and Berryman's B-12 carb cleaner as non-residue cleaners for decades now. All work great.

-- Mistrust the man who finds everything good, the man who finds everything evil, and still more the man who is indifferent to everything. -- Johann K. Lavater

Reply to
Larry Jaques

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