Rolf's TL-1A

[JimC]

For another occasion I recommend the brown mylar parcel tape. Epoxy doesn't stick to it and we use it extensively in boat building circles for ad hoc moulds. Rather then the original pickups I suggest using balsa wood wrapped in parcel tape, because it can easily be removed after the epoxy has set. I think in this application I would mix microfibres, sawdust or sanding dust in with the epoxy to make it easier to screw into.

[RocknRolf]

Whoa, that's one way to do it!

I glued small dowels in the corner of the cavity of my Sonicaster so I could use a pickup ring.

Yeah thought about that Sonic! But as the screw holes are right on the edge, I was afraid the bond of the dowel might break. The thought about shaping bits of soft timber in the corners, but that was more work then using epoxy to fill :-).

For another occasion I recommend the brown mylar parcel tape. Epoxy doesn't stick to it and we use it extensively in boat building circles for ad hoc moulds. Rather then the original pickups I suggest using balsa wood wrapped in parcel tape, because it can easily be removed after the epoxy has set. I think in this application I would mix microfibres, sawdust or sanding dust in with the epoxy to make it easier to screw into.

Thanks Jim, always good to hear other options for the future, never knew mylar tape does not bond with epoxy. I thought about using a block of wood, but I had to shape it to the shape of the pickup, and to be honest, I thought it be safe to wrap the pickup and lift it out as the epoxy went off.
The epoxy I used is mixed with glass bubble filler and small glass fibres, I recon it should be strong enough for a screw to hold the pick up in place.

We'll see how it goes. If the screw holes does not hold, I know I should've taken a bit more time and add saw dust and more fibres.

[McCreed]

Have you extricated the pickup yet? Did it come out clean? Do you have any "after" pics?

[RocknRolf]

Yes I pulled out the pick up as the epoxy was setting (so flexible enough to pull out, but stable enough to sit on itself).
Had put a little string around it, so I could pull it out straight.

One thing offcourse was the wiring holes, I need to redrill them again, and during injecting the Epoxy, some of it went in the hole, but I can't see that being a major issue. Trick is to inject the epoxy a little late, so it wouldn't run out. Looking back I might've well just taped it.. Reflecting on this I don't know why I did that, I am always working really neath and tidy

[McCreed]

Looks good. This seems to have done the trick for you!
Like many things guitar, there are more than one way to get a job done. I always appreciate others' ingenuity in problem solving.

Cheers

[RocknRolf]

Ow absolutely, and that is why I love forums like this one, everyone speaks their mind and it brings you to new insights.

[Simon Barden]

I suggest drilling decent sized pilot holes as the epoxy won't have as much give as wood, and is liable to split if you let it get too hard before drilling and putting some screws in. Don't drill the holes too short.

I suggest doing that (with some grease or wax on the screws) before the epoxy fully hardens but is solid enough to retain its shape.

[JimC]

Shouldn't crack if there's lots of glass fibres in it unless the screw hole is very small. Its as likely to take the screw head off, which is no better of course.

Standard tube epoxy, araldite and the like, are heavily filled with silica. As well as very thixotropic before cured, it also makes for a very hard but brittle cured layup.

Cured epoxy itself is pretty flexible - indeed its one of the reasons why its a better resin than polyester. Cured with microfibres - which are cellulose based fibres - the end layup can be very flexible. Glass bubbles are mostly bulk, but I've never explored how well they take self tapping screws. Maybe I should make some test pieces next time I do some epoxy. With the boat stuff I've always used through bolts when I can and hardly considered self tapping screws. But it can only be a good thing to get screws started while the epoxy is still green.

[Later] Been reading up some boat building manuals. The most favoured option seems to be to put self tapping screws into uncured epoxy. That's a pain for us in guitars since we want screws to be removable. The solution for that was to dip the screws into a release agent before installing. The method would be to put the epoxy filling piece in, let it cure, and then drill a hole in it and put fresh epoxy in the new hole. Feels like a load of hassle. Possibly better, if you have taps, to tap a hole in the epoxy and use machine screws rather than self tapping screws.

[DarkMark]

I looked up ‘thixotropic’ and I still don’t understand what it means.

[king casey]

I looked up ‘thixotropic’ and I still don’t understand what it means.

Here ya go https://en.wikipedia.org/wiki/Thixotropy

Also stop yer onions from falling out of the Bunnings sanger and disrupting the OH&S policy.

cheers, Mark.