Installing threaded inserts without d... Log Out | Topics | Search
Moderators | Register | Edit Profile

Alembic Club » Owning an Alembic » Troubleshooting » Archive through November 30, 2011 » Installing threaded inserts without damaging finish « Previous Next »

Author Message
dfung60
Senior Member
Username: dfung60

Post Number: 496
Registered: 5-2002
Posted on Tuesday, June 28, 2011 - 10:26 pm:   Edit Post

Hey everybody -

I was just going to do a little work on one of my non-Alembics, and I thought I'd collect some input from the hive mind.

You guys know that I've got a big collection of instruments, including a lot of really exotic stuff. So, it might be a little surprising that my go-to bass for many years now is pretty pedestrian. It's a Modulus BassStar that's basically a P-bass clone with a Modulus graphite monocoque Jazz Bass neck and a single EMG P pickup. The body is "plain old wood" with Lake Placid Blue metallic paint and there's just volume and a passive tone knob. I love the way it sounds and feels, and I wasn't terrified to take it out until I realized that it was probably my #1 bass... It's fairly old (probably around 1979-80) and probably wasn't built at Modulus.

Anyway, because of the EMG, there's a 9V battery onboard, which was just crammed under the pots causing the pickguard to bulge up. I thought about routing a battery compartment in back, but didn't want to cut it up that much. I also thought about cutting a cavity on the front that would be hidden by the pickguard. But, after some measuring, I think it actually will work to deepen the control cavity rout a bit to create a little more room under the tone pot and jack, sort of where it's crammed in now.

While I'm in there, I will also fix some of the pickguard holes that cracked the body wood in the area of the bulge. In normal Fender style, some of the screw holes in that area are on little "peninsulas" of wood in the control cavity, and they've completely split over the years. So, I'll cut out the existing areas and glue in some new wood in it's place.

I still have to pull the pickguard to change the battery, so I decided I'd replace threaded inserts and machine screws where the wood screws are now, a la Alembic.

I found Mica's page on how they install threaded inserts (http://alembic.com/club/messages/16271/32492.html?1161211796) and have purchased the inserts and stainless oval head 4-40 screws for the project. The instructions are great, but before I start doing this, I was wondering about ways that I can minimize the chances of chipping the finish.

The threaded inserts are MUCH larger than the old wood screws, so I need to be very careful when increasing the size of the holes and getting all 17 of them right. On Alembics, the inserts are being inserted in areas that have finish, but the inserts are covered by plates when they're done. That's the case for my bass as well, but the pickguard doesn't extend all that far past the screw holes, so I really don't want to crack the finish. There's minimal danger from the drill bit tearout, but when screwing the insert into the wood, I'm concerned that that will put a lot of stress on the finish.

I definitely will do this with a new, sharp bit and I know that taping over the drill point helps keep things together. The safer way to do this is to hold a piece of wood down on the surface and drill through it first, but I don't think this is going to work for me since I'm not drilling a new hole, but finding an existing one.

Any suggestions are appreciated!

Thanks,

David Fung
elwoodblue
Senior Member
Username: elwoodblue

Post Number: 1241
Registered: 6-2002
Posted on Tuesday, June 28, 2011 - 10:59 pm:   Edit Post

Have you thought about using a block or plate that's been predrilled ? .... lining it up to the existing hole.

Fine project David (gotta love threaded inserts), I really enjoy my BassStar fretless J-bass.

Elwood
terryc
Senior Member
Username: terryc

Post Number: 1617
Registered: 11-2004
Posted on Wednesday, June 29, 2011 - 10:22 am:   Edit Post

david..I would go with elwoodblue, make a jig with a hole the same size as the insert, this is your guide, clamp it firmly over the finish to prevent it lifting.
Ideally if you have access to a pedestal drill with a very high speed, that way the hole will truly be vertical, there is always a chance that there will angulation if you use a hand drill.
By the way did you check out my back plate I made in the 'Alembic basses...' section.
dfung60
Senior Member
Username: dfung60

Post Number: 497
Registered: 5-2002
Posted on Wednesday, June 29, 2011 - 4:12 pm:   Edit Post

Thanks to both of you for the suggestions. I had considered using a predrilled block of thick plexiglass as a drill guide, but securing so it's firmly on the surface is pretty challenging - many holes, many near the curved edges of the body. The guide would help make sure the hole is straight too, as I don't have a drill press.

Maybe this isn't a good idea - there's only 1/4" between the pickguard holes and the edge of the pickguard, so for the 3/16" insert hole, there's only 1/8" clearance maximum...

Thanks!

David Fung
adriaan
Moderator
Username: adriaan

Post Number: 2819
Registered: 6-2002
Posted on Wednesday, June 29, 2011 - 11:16 pm:   Edit Post

Perhaps an option to get a new pickguard, with no holes pre-drilled. Install the inserts with a reasonable margin of comfort, then drill the holes in the pickguard to match.

If you can't find a hole-less pickguard, you could follow terryc's example and construct one out of a couple of wood veneers.
adriaan
Moderator
Username: adriaan

Post Number: 2820
Registered: 6-2002
Posted on Wednesday, June 29, 2011 - 11:26 pm:   Edit Post

... and perhaps reduce the number of screws. Surely one does not need 17 of them to hold down a measly scratchplate!
terryc
Senior Member
Username: terryc

Post Number: 1619
Registered: 11-2004
Posted on Thursday, June 30, 2011 - 3:22 pm:   Edit Post

adriaan..I agree 17 is just overkill

Topics | Last Day | Last Week | Tree View | Search | Help/Instructions | Program Credits Administration