LSi tower wobbly spike anchors

sk88

It's been annoying to me for a long time to have shaky spikes under the speakers because of the anchors are loose. Several anchors are also not mounted flush to the bottom panel so that the spikes can not properly screwed on to flush with the panel.

I tried different ways to remove those anchors but was not successful as you can see the scratches I made in the picture. I had thought they were screwed in like other anchors. Then I realized by accident that you can push them out by keep **** in the threaded rod. Those anchors are actually hammered in, they are not threaded. Once you pushed them out, you can replace them with threaded anchors or just apply some gorilla glue on the sides and hammer them back in. Gorilla glue expands as it dries so it applies pressure to hold the anchor tight in place.

I would guess the anchor is the same for LSi 15 and 25. Not sure if this is a common knowledge but thought I share.

F1nut

A high grade epoxy would have been a much better choice.

sk88

I am sure epoxy provide much stronger adhesion. But does it expand? Because the anchor is loose so there are gaps in the hole, expansion may provide stronger result than just adhesion.

sk88

Hi Finut, can I ask you a side question? Since I unscrew my speaker drivers often, those holes on MDF loose tightness over time. Is there something I can drop into the holes so they won't get loose but would still allow me to screw/unscrew the drivers? I am not thinkig of toothpicks, but something like acrylic or polyurethane paint or something.

WLDock

Carpenters wood glue and sawdust works well for this. Also, Bondo fills MDF very well.

F1nut

sk88 wrote: »

I am sure epoxy provide much stronger adhesion. But does it expand? Because the anchor is loose so there are gaps in the hole, expansion may provide stronger result than just adhesion.

You would fill the hole with enough epoxy so that when you insert the anchor the epoxy oozes out, then wipe off the excess. There are also fillers available that thicken the epoxy. Check out West Systems Marine epoxy.

Since I unscrew my speaker drivers often, those holes on MDF loose tightness over time. Is there something I can drop into the holes so they won't get loose but would still allow me to screw/unscrew the drivers?

Hurricane nuts would be perfect. You insert them from the backside by using a machine screw or cap screw to pull the nut into the hole. Do not over torque the screw when installing the nut. You may have to drill out the holes in the bezel a little bit first. You want the hole to be slightly smaller than the Hurricane nut shaft so that the burrs grab the MDF. To mount the drivers you'll have to buy new machine or cap screws in the same thread pattern as the nuts. Parts Express sells the Hurricane nuts. The most common thread pattern would be 1/4-20.

If for some reason when installing a Hurricane nut you find that it spins in the hole, use a bit of 5 minute epoxy on the flange and shaft of the nut, let it set and you're good to go.

Once done, your drivers will be coupled to the bezel much better than before and you should notice a slight improvement in the overall sound quality.

sk88

WLDock and F1nut, thanks for the tips. Appreciated.

I did a little follow up on hurricane nuts and as F1nut mentioned that the size of the hole and a little epoxy are very important.
http://techtalk.parts-express.com/showthread.php?227535-Rant-I-hate-hurricane-nuts!!!!!

jon s

Definitely use epoxy when installing hurricane nuts... If the nut gets loose or strips the MDF after you install the speaker, you will NEVER get the speaker back out without destroying the cabinet...

sk88

I saw some people say if the nut get loose and spins then have to cut off the screw head with a Dremel to remove the speaker and then push the nut inward on the outside and catch it when it falls off on the inside.

I've not done any of these. I am thinking that I may just drop some superglue into the holes not to fill up the holes but just enough to harden the surrounding MDF. Is this a good idea? In my case, the screws aren't loose yet, but I am trying to do some preventive measures to prevent them from getting loose.

F1nut

sk88 wrote: »

I did a little follow up on hurricane nuts and as F1nut mentioned that the size of the hole and a little epoxy are very important.
http://techtalk.parts-express.com/showthread.php?227535-Rant-I-hate-hurricane-nuts!!!!!

Man, those guys sure have a lot of problems. Of course, that first guy's mistake was using Gorilla glue.

F1nut

I am thinking that I may just drop some superglue into the holes not to fill up the holes but just enough to harden the surrounding MDF.

Super glue is too brittle for that. Hurricane nuts are the way to go, IMO.

WLDock

Yes, super glue is NOT what you want to use. Cabinet makers and car audio installers have been using carpenter's glue and saw dust for ages to repair minor stipped holes. Done it many times myself...don't take my word...go over to a cabinet makers forum, etc.

If things are major, use Huricane nuts with a little bit of epoxy......these are much better than T-Nuts....which suck for use in MDF IMO! It almost sounds like the guys over at PE were using T-Nuts! LOL!

sk88

I appreciate all the suggestions. However, my situations is that the screw holes are not stripped or even loose yet. To use hurricane nuts would require me to drill the holes which would be a irrevocable solution that I only want to use as a last resort. And I am not sure how can I apply the sawdust/glue mix evenly into the hole without filling up the entire hole. I am just trying to come up with a preventive way that can harden the MDF hole surroundings (but not filling up the hole) so they won't get loose easily (a novice theory).

In some online search I found that thin CA (low viscosity superglue) and synthetic lacquer have been mentioned. Not sure where I can find synthetic lacquer? Epoxy heated with heat gun or hair blower to help it flow to get absorbed by MDF was also mentioned. Is there a particular epoxy that's "thin"? I have some scrap MDF that I can do some experiments.

sk88

This may be for the lacquer solution. It's alcohol based so will not swell the wood. Some people said their MDF can soak in from 1/8" to 1/4".
http://www.homedepot.com/p/Zinsser-12-oz-Clear-Shellac-Spray-408/100176744

I also talked to West Systems and they suggested the following:
- mix 5 parts of 105 resin with 1 part of 206 hardener
- warm up the wood
- swap on the mix and let it soak in as the wood cools down
http://www.amazon.com/West-System-Epoxy-Handy-Repair/dp/B002IZDOCG/ref=sr_1_2?ie=UTF8&qid=1377196351&sr=8-2&keywords=west+system+epoxy+repair+kit

pitdogg2

sk88 wrote: »

I saw some people say if the nut get loose and spins then have to cut off the screw head with a Dremel to remove the speaker and then push the nut inward on the outside and catch it when it falls off on the inside.

I'd want to stay as far away from this as possible. Epoxy first with the correct hole size you're golden.
Can't imagine what that guys speaker basket or surround looks like.

If you think about it most speaker manufacture's in the 60's-70's used T-nuts stapled inside the cabinets. I think most dropped it as it was an extra expense and when particle board and MDF came along they would not hold well and would weaken the surrounding area.
Hurricane nut are much better IMHO

sk88

I have no question that hurricane nuts is the better way to repair loose spinning holes. But I am just trying to do some prevention as I mentioned in my last post, I'll try either the lacquer or the epoxy methods.

WLDock

The hole becomes loose because the small particle that form MDF start to work away everytime you remove and replace the screw. Taking a toothpick of the fine sawdust/glue mixture into the hole will add more surface back. You don't have to put in so much that you completely fill the hole. However, if you do fill the hole...no problem! Just drive the screw into the now much tighter new hole. You can do this over and over again.

How much do you remove your drivers? If a lot, why? Are you modding the crossovers? If so, there is a better way! Wire them outside of the cabinets. Just taking a wild guess.

pitdogg2

sk88 wrote: »

I have no question that hurricane nuts is the better way to repair loose spinning holes. But I am just trying to do some prevention as I mentioned in my last post, I'll try either the lacquer or the epoxy methods.

I fixed some holes in a pair of Cerwin Vega D7's by mixing epoxy(liquid) then taking toothpicks and filling the hole good then cutting toothpicks down and also inserting them. After it dries good I drilled out a screw hole a little smaller than that screw. it worked very well actually. Completely understand taking it 1 step at a time.

sk88

WLDock wrote: »

How much do you remove your drivers? If a lot, why?

I am making a XO mod which will be external, and I will be trying Blackhole 5 and Dynamat to see if they do anything good (just because I have them). I think I'll try shellac or epoxy as they would "soak in" so hopefully will harden the MDF. If the screws still get loose later, then I can always use sawdust/glue . I'll keep hurricane nuts in my back pockets if I have to use them at some point but I hope that won't happen.

As pitdog says, one step at a time

sk88

F1nut wrote: »

that first guy's mistake was using Gorilla glue.

Loud and clear :biggrin:

Gorilla glue is like Boss speakers, they are good to a point. :cheesygrin:

F1nut

I just want to point out that one of the benefits to using Hurricane nut is they will couple the drivers to the bezel much better than is possible with wood screws.

sk88

Roger that. I picked up a box of Mortite last week, hopefully it will help with coupling. I guess I'll find out if those wood screws are tight or not when I press on the mortite.