Pioneer HPM-100 Restoration Project (Veneer removal)

Keating

New Member
I purchased these Pioneer HPM-100's cheap and was inspired by several restoration projects from this site. My goal entering this project was to make them better than new, if that's possible, so here goes.
 
20180629_173520.jpg 20180629_173528.jpg 20180629_173538.jpg 20180629_183116.jpg 20180629_183120.jpg 20180629_183922.jpg 20180629_185018.jpg 20180629_175057.jpg 20180629_173520.jpg 20180629_173528.jpg Before Pictures. Sets #1 and #2. As you can see they are in very rough shape. The previous owner didn't treat them well, and it appeared he moved parts from 200W version to 100W version to have the best cabs. He had three sets. I purchased the worst of the three. Started by removing all the drivers and inspecting the damage.
 
I decided the best coarse of action was to completely remove the veneer. This makes the project even more challenging. Removing the veneer was not possible by simply using acetone. I was able to achieve this on the veneer strips on the front of the cabs. Pioneer had some quality adhesives back then I suppose!!

I achieved this with a belt sander and palm sander. The results were good but was careful to not remove too much. 20180630_150719.jpg 20180630_153100.jpg 20180630_153106.jpg 20180701_072736.jpg
 
It was blazing hot out, so I took opportunity to repair the grills, grill covers and affix new grill badges. The grills were similarly over built with over 100 staples per grill. I removed these carefully with a small flat head screw driver. I repaired some splitting and fashioned a new cross member pieces the previous owner decided to remove. It was probably rattling. I went with replica grill badges, because I don't want to punch a hole in the new synthetic grill clothes. These replica badges are exact copies without the mounting post. These mounting posts also loosen with age, so you will see sets out there with the badges not straight. The Pioneer grill clothes have a more cotton/synthetic blend and are thick. Maybe 2-3mil. The new grill cloth is thinner, maybe 1mil, which I wanted, to allow me to see thru the grills. This will allow the drivers to be barely visible with grills installed.20180705_155424.jpg 20180705_163427.jpg 20180705_164110.jpg 20180705_164425.jpg 20180705_164750.jpg 20180706_021932.jpg 20180706_022116.jpg 20180706_022535.jpg
 
Cabinets have been repaired. I used the wood bondo as a leveling agent, so I don't remove to much of the wood underlay. All of the corners are now true and used a level to make sure all sides were plumb. 20180707_174548.jpg 20180707_174559.jpg 20180708_100009.jpg 20180708_100016.jpg 20180708_111104.jpg 20180708_111116.jpg 20180708_111122.jpg
 
Attention to detail is a must. Including hardware. The previous owner damaged/marred all the driver hardware moving them around. After a lot of research I found a vendor who sells the exact bolts and washers. This wasn't easy. Most black oxide pan heads in this size are now hex key design.

Monster-Bolts.com (Ebay Seller)

Woofer - 4ea per speaker, M6 x 40, #3 Phillips, Pan Head, Black Oxide, Machine Thread, DIN 7985AM4.jpg M6.jpg
Mid/Tweeter - 8 ea per speaker M4 x 35, #2 Phillips, Pan Head, Black Oxide, Machine Thread, DIN 7985A
 
Decided to fabricate a new spec sheet and laminate it for the rear cabinets. Laminated it to prevent tearing. Used PDF format for high res printing, and transferred the MM/YYYY info to the top of the sheet near SN info. Sheet size from Pioneer was 10 x 7", and I used Arial Terminal Font, 30 point, to match original Pioneer font and size. My speakers were MM-YI-28469 Q and MM-YI26543 Q, indicating they were made in Sept 1978.20180706_050711.jpg
 
I upgraded the crossovers20180629_185356.jpg with new Dayton Caps and resistors. I tested these before the cabinet restoration work began. I used a build spec created by others from this site. Very detailed and quite easy. Not going to go into a lot of detail regarding the electronics but highly suggest you upgrade your crossovers with modern caps/resistors.
 
The dust cap on my mid driver had a dent. No problem. Made a straw out of a ball point pen, wet the dust cap with alcohol20180708_190911.jpg 20180708_190948.jpg 20180708_190954.jpg 20180708_191009.jpg and some water and 5 sucks it was good as newish..
 
Don't sand off your Pioneer "Passed" Inspection Stickers. Tape over them before repainting the back of the cabs. 20180630_111713.jpg 20180630_111717.jpg
 
4 x 8' raw Walnut veneer sheet, no backing, 3/16". These are speakers so I opted for thicker veneer. This isn't a TT Plinth 1/40 peel and stick veneer. Will adhere with spray adhesive and J-Roll it. Here are my supplies. UV Dye, Gel Stain, Gel Coat and Gloss Finish. Yes they will be gloss. That's what I want. 20180629_170220.jpg 20180629_170231.jpg 20180708_112247.jpg
 
Screenshot_20180709-122935_Amazon Shopping.jpg I've decided to not use spray glue with this project. Instead I'm switching to Adhesive Gel. It has the consistency of grease but goes on like paint. This will assure I have no lumpiness under the veneer.
 
View attachment 1230975 I've decided to not use spray glue with this project. Instead I'm switching to Adhesive Gel. It has the consistency of grease but goes on like paint. This will assure I have no lumpiness under the veneer.

Good choice. I used original Weldwood Contact Cement for my veneer project and it worked fantastic. Be sure to use a roller to apply it - a brush leaves uneven applications behind and will create the very lumps you want to avoid. Coats that are too heavy will do the same. (Ask me how I know :dunno:) I learned to apply two medium-light coats to both surfaces, allowed to dry to the touch before bonding. Followed that with a veneer roller, which proved essential to the task.

Looking forward to seeing your work with that gorgeous veneer you've chosen.

GeeDeeEmm
 
Looks like you're going about things the right way to me. I've got 2 or 3 sets which require the same repairs, but are patiently waiting there turn. Thanks for the tip about where to source the screws and taking the time to document and photograph your project. Your procedures will be helpful for anyone looking to remove and replace the veneer on their cabinets. :thumbsup:
 
Looks like you're going about things the right way to me. I've got 2 or 3 sets which require the same repairs, but are patiently waiting there turn. Thanks for the tip about where to source the screws and taking the time to document and photograph your project. Your procedures will be helpful for anyone looking to remove and replace the veneer on their cabinets. :thumbsup:

Wanted to give something back. Learned so much about the hobby. You wont find that screw info anywhere else. Save this.
 
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