Loctite for drilling

Hi,

So I am thinking of using Loctite to 'tack' parts (castings) together so I can drill them accurately. I figured this is probably one of the easiest ways to hold parts with complex clamping arrangments....

So - is this a good idea or not? If yes, what Loctite would you use keeping in mind the parts need to be separated later and the Loctite cleaned off.

I was thinking 641???

Thanks

Matt

I just use ordinary super glue. Way cheaper than Loctite

Holds a 60mm piece of Ali to a disc strong enough to allow machining on the lathe.

Bruce

I don't recommend using Loctite its not really for that usage as Bruce said better to use industrial Super Glue or Double Sided Tape, if its heavy machining I would prefer soft solder if possible, I have had glue when warm let go.

Stan

There are Loctite super glues, and other adhesives, not all Loctite is designed to lock threads or shafts, but the Loctite super glue will cost a good bit more than the stuff you normally get at the hardware shop.

Ian S C

I am in the process of fitting a key to the base of my big machine vice for quick location in the table slots. I milled a 1/2" slot in the vice base to give a close fit on a bit of 1/2" BMS square, then used Loctite high temp fixing stuff to lock the bar into the slot to drill matching holes. Worked a treat, after drilling the bar could be knocked out with a drift quite easily. Of course in this application the sides of the slot constrained the bar sideways so the Loctite wouldn't need to work that hard.

I have found previously that if I Loctite something in a through hole and place the whole item on a flat surface to cure and some of the stuff leaks through the hole, it does fix quite firmly to the surface but the bond can easily be broken. I'd say give it a whirl - maybe on a test piece first.

Problem with superglue is that it does fix fast, only way to break the bond can be to apply heat, the whole assembly may need to be got quite hot, and the fumes are very nasty.

If the surfaces are nice and flat, another option I've been trying recently with some clock parts is shellac, in the form of carpenter's knotting. You need to apply quite a lot to fill between the items, then leave it somewhere to dry, preferably a hot surface like a storage heater. This can hold well once set and cold, to release get it quite hot again, around 80 - 100 C, when the shellac softens. In one case I boiled the items! Knotting comes in quite large bottles, is cheap, lasts for ever, and safer than superglue. Get it off with meths.

Not all superglues require heat to break the joint, I ocassionaly "glue" a brass shim to chuck jaws to save marking or as a spacer (if things are heavy and you do not have extra hands, this is a way around it). Light tap breaks it clear, nothing harmed and I do not degrease anything.

They do a large range of super glues. I'm fond of the thixotropic grades. Also grades for gluing specific substances together. As they seem to me to often work a lot more effectively than some that are about and come in fair sized bottles I'm not sure they are that expensive really.

John

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I think it could work with loctite, you might want to think about what you would use to clean it but a wire brush held in a bench grinder/lathe spindle would get all the gunk off, but remember to be careful when polishing objects offhand in the lathe.

Michael W

Thanks for the responses all..... What I am trying to do is just hold a few pieces together while I gently vertically drill through them (Cylinder and valve chest for example). The parts will be a close, polished fit so from what everybody has said, I imagine a spot of superglue on each side would work nicely. I guess the part would easily separate when needed and then the glue sand off...

Having said that, I like the idea of double sided tape - I have used this technique for turned small parts before so I might try that!

Thanks again

Loctite is a trade name and they make a myriad of different products, some are bearing securing adhesives, some are stud locking adhesives and they even make a super thermally conducting copper loaded RTV for superheated steam. So perhaps it would be better to instead use the correct name for the adhesive rather than the generic trade name?

John,

I almost wrote your words last night, but then realised that the original post does mention 641. So I decided to just 'observe'.

That said ... the thread has drifted into the usual ambiguity, and yours is a very timely 'wake-up'

MichaelG

Edited By Michael Gilligan on 02/03/2016 16:33:12

Most locktites above medium strength will be ok for drilling and mild milling.
I normally use bearing lock just heat up to take apart. If milling and generating that much heat your doing something seriously wrong.

Most super glue should be ok for drilling.
Used to cnc 1/2" thick plates in steel down to 1/8" but had to take mild cuts.

Double sided tape may be ok for diy but OP stated close fit parts.

I would imagine most double sided tapes wouldn't have enough "tack" to withstand the twisting effect of drilling without more support.

Michael W

...so just for feedback, I used some scotch double sided tape....very thin, not overly tacky but sufficient to hold the parts together for drilling. The holes where only 2.3mm anyway so not much turning force - but worked out well.!

Of course this strategy would not work on a rough casting, only on machined finishes.

.

I recently tacked some parts together so that I could machine them as pairs. - The material was aluminium and I found super glue was a good bond with this.

I also used super glue for bonding a steam chest, it's lid and the cylinder together for drilling before I had a DRO on my mill to be assured of all 3 matching.

Double sided tape is I know used when turning thin material on a lathe faceplate. As far as I am aware the strength of the bond while machining is not the problem. Getting the bond to break and get the thin part off without bending it may however be so.

Nick