L-100 fund raiser project

[Don C]

Hmmm, we might do better auctioning a pair of NS-10Ms.

[bob newton]

WHO'S KIDDING WHO?? BO ALREADY BOUGHT THEM!!

[scott fitlin]

WHO'S KIDDING WHO?? BO ALREADY BOUGHT THEM!!

[Audiobeer]

I think putting them on Ebay is a fantastic ideal!

[bob newton]

I think putting them on Ebay is a fantastic ideal

Maybe, maybe not

[jlovda]

I would like to ask AudioBeer some questions as I would like to begin a similar project on a pair of L-88P speakers with a DIY midrange upgrade using LE5-8 mids. These speakers have the same front grille frame so I will see if I can get a set of replacement foam grilles.
1. What did you use to strip the old finish off?
2. What was your technique with the steam to get scratches out? Did you use a drapery steamer? How long did you apply the steam? I assume you have to be careful not to lift the veneer off the base wood. Did the scratches literally swell up to surface level or were there still some residual marks? Did the scratches completely disappear after sanding? Did you have to use any filler on edge chips, etc?
3. Did you use a rotary palm sander for your work? What grade of sandpaper did you work with?
4. What brand and color name of stain did you use? I once tried Minwax "Special Walnut" but it was much too light.
5. It's hard to tell with pictures but how close do you feel you came to the original JBL cabinet finish? The JBL walnut finish is quite dark and very flat with virtually no sheen. Even "Low Sheen" Tung Oil seems to look like varnish in comparison. What did you use on top of the stain?

Thanks for your help. Your pictures look beautiful. You did a great job!
John Lovda

[Audiobeer]

Give me a day to respond as I just read this and it's late. Thanks!

[Donald]

Mr. Beer,

I look forward to your answers. I have 2 pair of L100 cabs that need work. With some information in hand I might actually start! :dont-know

[Audiobeer]

I would like to ask AudioBeer some questions as I would like to begin a similar project on a pair of L-88P speakers with a DIY midrange upgrade using LE5-8 mids. These speakers have the same front grille frame so I will see if I can get a set of replacement foam grilles.

Grill frames won't be a problem but the foam will be. There just isn't a call to make replacements for this model. Think of how many L100s were made and getting good replacement is like pulling teeth.

1. What did you use to strip the old finish off?

I don't like wimpy strippers! I use aircraft paint stripper from the auto parts store. If used carefully saves time and is water soluble. If however there are no scratches to a finish, I will use anyting like acetone or laquer thinner with gloves and of course a lit cigarette.

2. What was your technique with the steam to get scratches out? Did you use a drapery steamer? How long did you apply the steam? I assume you have to be careful not to lift the veneer off the base wood. Did the scratches literally swell up to surface level or were there still some residual marks? Did the scratches completely disappear after sanding? Did you have to use any filler on edge chips, etc?

That answer varies depending on the type of scratch. If it went through to the cabinets veneer then steaming will only help close the scratch, but not solve the problem. You see wood being a cellulose creature has those cells compressed or crushed if you will when they get scratched or marred. By steaming you are in a way inflating those cells thereby restoring their original physical size......almost. After steaming I have mearly applied a little scuff sanding to a light scratch and it was restored without any tell tale signs. In most cases you will elevate the scratched area and sand the area around it equalizing both the veneer levels and the patina. I always use a common household iron. I take a rag that is clean and dip it in distilled or bottle water. Tap water is fine as long as you know there is no heavy calcium or chemicals. Dampen the area to the point of saturation but not heavy enough to have it dripping. Take that same rag, lay it right on top of the scratch and move the iron over the top of the flat rag like your flattening out pizza dough. Your trying to do 2 things.......get that steam in the scratched area and at the same time trying to distribute the steam and heat around the area as to not leave a change in the woods patina that isn't shared equaly around the scratch. Let it dry in 15 minutes and block sand the area you worked with 120 grit cabinet paper. But before doing that I try to hand sanding what is left of the scratch, seeing if whats left of its definition can be reduced any more. If done properly you will not have any adhesion issues.


3. Did you use a rotary palm sander for your work? What grade of sandpaper did you work with?

I do use a rotary sander for finish sanding but never over any topcats. If you let the sander do it's job and not force it, you will not see the tell tale signs of modern tools! I start with 120 or 150 and step up in increments. normaly on 4313B, 4311, 4312, 4343, or l220s and any speaker pre-dating the junkfest I use 150, 180, 220. Now when you get into the pro monitors of recent history I would recommend passing on refinishing. Take a 4412 for instance. The veneer is so paper thin that a novice or pro can go right through the veneer.

4. What brand and color name of stain did you use? I once tried Minwax
"Special Walnut" but it was much too light.

I use Mimwax and other oil stains. I like them as the pigment floats into the pores and conditions the woods. The paste or gel stains can be ok, however I see some clouding when I have used them. To achieve the stain for JBLs I have used provincial and golden oak in a 50-50 mix.

5. It's hard to tell with pictures but how close do you feel you came to the original JBL cabinet finish? The JBL walnut finish is quite dark and very flat with virtually no sheen. Even "Low Sheen" Tung Oil seems to look like varnish in comparison. What did you use on top of the stain?

Top coating is a decision based on tastes. Stain it and make a linseed oil mix if your looking for a close match. JBL used that approach as well as cellulose laquer on later runs. It's whatever you want. I use whatever the customer wants. You can apply a cellulose laquer for instance on a cabinet using a dead flat laquer and hand rubbing and it will look just like an open grain oil finish. There are so many ways to achieve the results you want appearance wise.....so go with the one you feel most comfortable with.

Thanks for your help. Your pictures look beautiful. You did a great job!
John Lovda

Good luck to you and your project!
Mark

[jlovda]

Thanks so much for taking the time to write a detailed synopsis of your procedures. I am now eager to begin my February basement workshop project.

Your help has been invaluable.
John Lovda
Canton, OH

[Audiobeer]

[QUOTE=jlovda]I would like to ask AudioBeer some questions as I would like to begin a similar project on a pair of L-88P speakers with a DIY midrange upgrade using LE5-8 mids. These speakers have the same front grille frame so I will see if I can get a set of replacement foam grilles.

Try here! Scroll down the the section about speaker grill foam. They don't seem to have the original depression for the woofer but still look great!

http://cgi.ebay.com/ws/eBayISAPI.dll...748429078&rd=1

[wally44]

Audiobeer
Thank you for the comprehensive reply - and for sharing so many of your trade secrets! My L100's are in pretty good shape, but if, and when, I get around to rebuilding some that have been through the mill, your post will really be very very helpful.
Best wishes
Geoff S.

[jlovda]

AudioBeer made a comment about matching grilles for the L-88P. It is actually my intent to get a set of L-100 blue waffle grilles from the same source as he used. As far as I am concerned, once I put the midrange drivers in, there speakers ARE L-100's. The only unknown at this point is how to reproduce the L-100 thin aluminum front label with the mid/high level controls coming through.

Does anyone know where I can get two midrange L-pad knobs? These are the tiny knows with the screwdriver slots. I have two already from the tweeter L-Pads.

Thanks,
John Lovda

[Zilch]

Does anyone know where I can get two midrange L-pad knobs? These are the tiny knows with the screwdriver slots.

Look through the exploded tech manuals on the JBL Pro site for similars, maybe. 4425 is #52192, for example. Has a slot and a dot. Will that work for you? If so, buy 4 to be sure....

[Mr. Widget]

The only unknown at this point is how to reproduce the L-100 thin aluminum front label with the mid/high level controls coming through.

Does anyone know where I can get two midrange L-pad knobs? These are the tiny knows with the screwdriver slots. I have two already from the tweeter L-Pads.

The aluminum plates can be recreated, but the process is not inexpensive. L-100 cabinets turn up on eBay that have been parted out fairly regularly. You might be better off refinishing an L-100 cab that already has them on it and has the crossovers mounted..

A while back I was looking for those knobs myself. I managed to get them by buying up crossovers and then harvesting the knobs. JBL used those same knobs on quite a few speakers. I was able to get them for an average of about $5 each plus shipping.

Widget