Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: roboDNA on October 24, 2025, 06:30:17 pm

Title: Fender 6G15 Cabinet Build Tips
Post by: roboDNA on October 24, 2025, 06:30:17 pm
Hello,

I built a fender 6G15 cabinet from 3/4" baltic birch plywood ( tolex ) and it went well, so I now plan to build a 'super, super nice' one from eastern white pine an leave the wood exposed ( no tolex ).  The wood I plan to source from the local sawmill is older with tight rings with no knots ( standard C or standard D grade 'clear' pine ).  I plan to try air dried and kiln dried to see how they each adapt to my shop's climate.  I have the jigs for the 3/8" finger joints for tear-out free cuts.   I see some cabinets from '62 and '63 and the seem to have black paint inside but not sure if it should remain unfinished.  ( maybe just black face was painted black inisde? )

I"m sure I've missed some things to make it super nice and want to avoid finding out too late. 

Any tips on how I can raise the cabinet build to level 11? 

Thank you!
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: DeepBias on October 25, 2025, 01:51:58 pm
Seems a nice project, the original Fender 6G15 had the reverb tank suspended by springs over a piece of foam stuck to the board. The pan lock is pushing the pan all the way in so the foam mutes the reverb pan springs stopping them from moving in transport.
 
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: scstill on October 25, 2025, 06:37:57 pm
If you are going with a super nice exposed wood cabinet
I would suggest keeping the inside wood tone as well.
Just paint the front of the speaker baffle so it doesn't show through the grill cloth
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: roboDNA on October 26, 2025, 07:05:18 pm
I saw a nice 'hatch' mechanism somewhere for that 'tank transit bracket'.  You could reach in and unlatch it but some people often forget to unlatch for the live show apparently.  I read somewhere that bracket was only in the first few runs but not sure.  I'll add one of those FOR SURE. I was thinking of adding a light when the bracket is engaged.   Apparent the foam rots/degrades and crumbles away too?  Maybe leather instead of foam? 

I'll keep the inside wood tone, maybe even unfinished...

That leads me to another question:  Have you seen those metal 'ears' on some earlier builds?   The metal seems like a different type than the chassis, and it seems to attach somehow to to the main chassis but I have not seen any pics for it at the right angle.  I know the ears screw into the rear panel vertical posts.  I'm guessing the chassis on more recent models and clones are secured only by those 2 bolts going through the top and faceplate?  Maybe they figured that was secure enough and dropped the metal ears.

The baltic birch plywood one I built looks great on my bench with the baffle dry-fitted.  Just waiting on my deep-purple tolex :)

The eastern white pine one I started needs better pine.  The boards were slightly warped with small cracks.  Not dried correctly.  I plan on looking at premium pine boards this week and they should be the very best you can get.  No knots, no cracks, no warping, tight grain, clear pattern and good supply.   ( I'm at the doorstep of Algonquin Park in Ontario Canada and we have the really old/large pines here... I'm also trying to get my hands on some pine which has been submerged for over 100 years.  Those logs were too big/heavy for loggers to float them down the river here, and they happen to be the best ones  ) 



Title: Re: Fender 6G15 Cabinet Build Tips
Post by: dogburn on October 27, 2025, 08:37:38 am
The latching mechanism can be handy if you are transporting the unit a lot. Have you seen the design that Uncle Doug came up with for engaging the damping foam? It's at ca. 14:00 in this video:
&t=1466s
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: scstill on October 28, 2025, 03:15:24 pm
I recommend finishing the inside like you finish the outside for protection and looks.
But having said that, does anyone have an advantage (besides less work) to leaving the inside raw?
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: BrianS on October 28, 2025, 04:56:32 pm
Keep in mind that pine is soft and dents very easily.  Even with a nice finish, the wood will still dent easily.  Also, make sure there are coasters around for when your buddy wants to set his cold beer on top of your nice amp cabinet.
Tolex hides a lot of sins and takes a lot of abuse.
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: 8wattjack on October 30, 2025, 07:37:02 pm
 I wanted to leave some of my cabs raw years ago. Once I learned to do a descent job of tolexing, I tolexed everything. Even my couch.  :l2:
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: 8wattjack on October 30, 2025, 07:44:28 pm
If you really want to leave it raw, do a light burn on it then oil it. If you leave it shiny with a hard laquer or clear it won't stay that way long on pine. Burn it, oil it, and jam it!
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: DeepBias on October 30, 2025, 10:04:53 pm
... I'll keep the inside wood tone, maybe even unfinished...

Cleaning dust on bare wood surfaces is complicated  :smiley:
 
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: tubeswell on October 31, 2025, 11:13:31 am
 Use dowel inserts across the grain along the edges next to the cutaway (if making a tweed cab) to prevent the ends from splitting.
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: roboDNA on October 31, 2025, 11:55:19 am
Use dowel inserts across the grain along the edges next to the cutaway (if making a tweed cab) to prevent the ends from splitting.

Wow, this is a great suggestion.  Level 11 reached.  I can see how splitting of edge cuts is a weak point for non-ply/pine with finger joints. 
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: roboDNA on October 31, 2025, 01:15:52 pm
If you really want to leave it raw, do a light burn on it then oil it. If you leave it shiny with a hard laquer or clear it won't stay that way long on pine. Burn it, oil it, and jam it!

Great suggestion!  I did not even know about this process and it looks fantastic.  This seems to be the best finish if leaving the pine exposed. 

Title: Re: Fender 6G15 Cabinet Build Tips
Post by: roboDNA on November 03, 2025, 06:03:59 am
I'm just about to Tolex my baltic birch plywood cabinet and am considering painting the inside black first. 

Should I burn it and oil it, or is there a good black paint recommendation?   I want to make sure it's easy to wipe or clean.  Would something like Granotone be overkill for the inside?  ( note for my pine cabinet, I'll be burning and oiling )


Title: Re: Fender 6G15 Cabinet Build Tips
Post by: tubeswell on November 03, 2025, 01:58:49 pm
I just use any old black paint inside. Same of the front and back of the baffle (under the grill cloth)
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: roboDNA on November 04, 2025, 06:31:07 pm
I just use any old black paint inside. Same of the front and back of the baffle (under the grill cloth)

For my plywood build, I ended up painting the whole inside and out flat black, including the baffle and back panel.

Any tips on cutting the Tolex corners for rounded 3/4" edges? 
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: glass54 on November 04, 2025, 07:03:32 pm
Hi robo,
Have a look at the attached YouTube link. There will be others if you do a search
 https://m.youtube.com/watch?v=ztBBHXlspmE (https://m.youtube.com/watch?v=ztBBHXlspmE)
Regards
Mirek
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: tubeswell on November 05, 2025, 01:42:12 am
What Mirek said.


Tolex the 2 sides first, then top and bottom.
 Carefully measure the length and width first to avoid having to trim off later.
Dry-mark the tolex lines on the bare wood to get everything neatly lined up.
The only remotely tricky bits are the corners, but that’s easy to master.
Use a fast setting and sticky contact glue and apply it evenly to the cabinet wood, and the back of each tolex piece. Allow to partially set to a tacky residue before quickly and evenly applying - using your carefully marked cabinet lines as a guide.
Use a hard dry roller (like a Lino ink roller) to firmly and evenly roll out any bumps on the exterior surface.
Title: Re: Fender 6G15 Cabinet Build Tips
Post by: roboDNA on November 05, 2025, 08:19:13 am
Good info. thanks.

Does the interior of the cabinet get hot enough to be concerned about the BEHR Premium Plus interior wall paint I used gassing off or causing smell?    That paint looks very good, does not smell, is 'bio friendly' and can be cleaned but I plan on trying Duratex for my next plywood build since it may be more durable when doing repair work.

@glass54, I did see that video but you'll notice his corners are not rounded  or finger joints:)  I'll look for more examples on youtube later today but could not easily find any with 3/4" rounded corners :)  I'm sure mine will come out just fine but just looking for the best technique.

UPDATE: Tolex glue does not adhere well to the black paint so exterior should be bare wood.