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  #16  
Old 03-29-2022, 05:46 PM
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You DO like a challenge, don't you!
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  #17  
Old 03-31-2022, 03:15 PM
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Default 1920s Regal parlor FULL REBUILD: What's up with this bracing

Here's what the top and back bracing layout looks like straight from the factory. The blue tape shows where the braces once lived. Regal's top bracing pattern is scarce to say the least. This was not universal but quite common on budget parlors from this period and was practiced by other factories as well.

The new top bracing pattern will resemble a modern ladder brace style with four braces total, punctuated by added reinforcement under the fretboard extension and a generous spruce bridge plate with rosewood cap sitting between the lower two braces at the sweet spot. New bracing will be quarter sawn sitka spruce.

The back bracing pattern on this 20s Regal parlor is very much like we would expect back bracing to look like today. Things haven'y changed much with back bracing over the years in my experience with old parlor guitars. Unlike top bracing, I tend to remove, shape and reinstall the original bracing to the back(after all mating surfaces are properly prepared). Unless the original back bracing is excessively split, dried or missing it will do a fine job for the next 100 years once the rebuild is complete.

There are some quirks about this parlor body that do bear mention. Quirks will need to be addressed sooner than later but catching them now helps me prepare for them when the time comes.

The most noticeable quirk is that the rim at the neck block is twisted, contorted to appear uneven or off-kilter. If this guitar body was a real person, the right shoulder sits higher than the left shoulder, which appears compressed where the rim and neck block meet. There's no evidence that the neck block has been removed from the rim in the past and re-glued improperly so I'm guessing one of two things has happened here. 1. This was a goof when the body was being assembled at the factory, or, 2. The top unglued/detached from the neck block at some point just enough to allow the force of the neck under string tension to contort the rim here.

We already know this guitar has seen major temperature and humidity variations which has caused softening and rehardening of glue around the rim. The second scenario seems plausible as well given that the lining immediately adjacent to the neck block on the bass side was already detached and flopping around inside the guitar body. If this section of lining failed at some point then the neck ended up being completely unsupported on the bass side. The absence of "roundness" where the bass shoulder meets the neck block is also telling of what compression might have produced where they join. The last three photos illustrate this little quirk from different perspectives.

I've come across this before and I'll need to remember that shaping the neck heal to the rim at the neck block come neck reset time must account for the condition. Otherwise, I'll drive myself crazy trying to make the neck heal sit evenly on the rim when in fact I'll need to shape one side higher than the other so that the horizontal neck alignment works properly with the sound hole and the bridge location. More on that later after the box is closed in and when the time comes to mate the neck to the body.

The only other comment worth making at this point is that the original softwood linings are crap and will be replaced with new, kerfed mahogany linings. New linings will not only make for a stronger and more dependable box but also allow me to clean the entire rim unencumbered by the linings, at least what's left of them.

Next post will talk about how to prepare the top for bracing giving it's roller coaster, wavy condition and why just sanding it clean and rebracing without preparing it in advance doesn't work.
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  #18  
Old 04-01-2022, 12:59 PM
RogerHaggstrom RogerHaggstrom is offline
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I always remove the bottom and not the top. It's the way I have always done it, without even thinking about why. The one benefit is maybe that the more visible glue line around the top is not affected.
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  #19  
Old 04-01-2022, 04:25 PM
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Just a thank you for your excellent documentation of the rebuild. Your comments, speculations & solutions are most welcome...
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  #20  
Old 04-01-2022, 04:53 PM
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This may be a silly question, Steve, but where do you find your guitars? There can’t be that many left in creaky, old Vermont barns!
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  #21  
Old 04-02-2022, 05:16 AM
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Quote:
Originally Posted by RogerHaggstrom View Post
I always remove the bottom and not the top. It's the way I have always done it, without even thinking about why. The one benefit is maybe that the more visible glue line around the top is not affected.
In 9 out of 10 cases I'm with you 100% but this box is so unstable that both top and back must be removed, cleaned up and then reglued proper.
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  #22  
Old 04-02-2022, 05:17 AM
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Just a thank you for your excellent documentation of the rebuild. Your comments, speculations & solutions are most welcome...
My pleasure, Moe. Enjoy the ride.
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  #23  
Old 04-02-2022, 05:23 AM
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This may be a silly question, Steve, but where do you find your guitars? There can’t be that many left in creaky, old Vermont barns!
Old parlors were plentiful and cheap on Ebay back in 1995 when I started in there but that's not the case any longer. Popularity of vintage parlors and more online shopping opportunities have pretty much done away with plentiful and cheap.

Some parlors find me through word of mouth and some I'll seek out should a customer order warrant a search outside my stock of old parlors in the shop's repair queue. This Regal parlor was purchased on Reverb, ill described as it was, for a hefty price given its actual condition.
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  #24  
Old 04-02-2022, 07:41 AM
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I'll be following this thread with interest. Thanks for taking the time to document and share this process with us Steve!
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  #25  
Old 04-04-2022, 03:07 PM
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Default 1920s Regal parlor full rebuild: Body breakdown, Step 2 address the top warping

When an old parlor top(or back) is so warped that it clearly will not just become flat on its own so that the new bracing can be installed, special measures must be taken to help the top return to its former condition. Please note that I'm not aware of any process that will help the top to return to perfect flatness but the process I've used for many years does a good job and has served me well.

The top will need to be cleaned of all glue residue, dirt, splinters, etc before going any further (Photo 1). I try to get as much junk off with a scraper or razor blade before I pull out the sander to finish the cleaning. The reason being is that everything attached to the top, but needs to come off, will gunk up your sandpaper or sanding discs. That said, I save and recycle "used" sanding discs for this very purpose. The recycled discs qualify for this heavy-removing task but no longer qualify for more delicate, swirl-free tasks (Photo 2).

Once the underside of the top is sanded clean it's now ready for a "spa day", or actually three or four spa days. To coax the warped wood to behave itself I sandwich a well-moistened top between two pieces of wax paper and then sandwich the wax-papered top between two pieces of 3/4" MDF and clamp it to death. The moisture really brings out the crazy-cool grain pattern of the slab sawn birch top. Photo 3 shows I'm about ready to sandwich everything together.

I boil up some water, drench a rag and lay the rag on the underside and let sit for a few minutes. I want to make sure that the wood soaks up as much hot water as possible so that it will be pliable and not crack when compressed. The wood is relatively thin, old and takes in moisture quickly. Once pliable it easily agrees to being compressed without damaging the wood. I set this aside for a few days to do its thing. The sound hole on this top was pretty warped so I might give it until Thursday before checking on it (Photo 4).

Cleaning the underside of the top did reveal some small hairlines but that those will be addressed once the new bracing pattern takes shape. I'm expecting the top to be relatively flat once the the process is complete. It does dry out on its own despite being squeezed tightly in a press that doesn't appear to let much air inside. After the heavy duty flattening is done I will keep the top compressed between the MDF boards with minimal pressure until I'm ready for new bracing. This last step will help keep the flatness from thinking about returning to its evil, warped ways. Before updated bracing begins I will confirm that the wood is completely dry and give it a fresh sanding before any glue hits the surface.

In the next post we'll take the back come off the rim and get it prepped for rebracing.
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  #26  
Old 04-06-2022, 05:40 PM
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Default 1920s Regal parlor full rebuild: Body breakdown, Step 3 remove & rebrace back

Today's job was to remove the back from the rim, prepare the back for braces, prepare the braces for the back and then glue everything back together. Removing the back from the rim and cleaning up the back in advance of getting a bracing makeover is the same process as we performed on the top. The back was not as gunked up with glue residue as the top was but there was a bit of hand-and-razor work before firing up the sander. (Photo 1)

I use 80 grit to prepare the back surface for braces. There were only two original back braces still with the guitar so I salvaged two more from my stash of vintage braces saved from prior projects to make up the four we need for this job. After the overall surface of the back is sanded clean I use an old cheese grater to scuff up the area underneath the original braces even more. This area generally comes out looking pretty smooth, even after sanding, so some extra scuffing is an easy way to improve the mating surface for glue. (Photo 2)

Determining the radius on back braces in old parlor guitars is hit or miss. The best estimate I could figure on this Regal is 20' so when the four old braces were cleaned up and sized for each position the bottom of each brace was shaped to 20' and checked on a simple radius template that use for this purpose. At this stage of the job, the back is ready for bracing and the bracing is now ready to be glued to the back.

Now it's time to get the clamping cauls ready to do their job. For any clamping task that is radius- or shape- sensitive I use 1/2" thick PVC strips that were sliced from a hugely heavy 4' x 8' sheet of PVC as clamping cauls. I have dozens of smaller pieces of 1/2" PVC, from 2" to 20" long, that represent the lion's share of the cauls I use in the shop. These PVC clamping cauls are dense enough to handle even the strongest clamps but still malleable enough to bend to the shape I need for the task. I select the length I need to support the size of the four back braces and then bend the 4 clamping cauls to the same 20' radius template I use to shape the bottom of the braces. (Photo 3).

I lay out all the cauls and clamps I'll use to glue the braces to the back in advance. I use Titebond original formula for anything that needs gluing in the shop. I apply a coat to the bottom of the first brace and then secure it in place using ratchet clamps at each end. Once all four braces are ratchet-clamped into position, I follow up with screw clamps to apply pressure to the rest of the brace. You'll notice that the smallest brace has one screw clamp and the longest brace has three. (Photo 4). The tops of the braces will get final sanding/shaping before the back is glued to the rim.

TIP of the DAY: Using the proper clamping caul for the job is huge. In this example, the clamping caul shape must mirror the underside shape of the brace its supporting, otherwise, I risk not having every possible fiber of gluing surface attached, not just firmly, but also where I want it to stay, always.

Next up we'll have a look at how the top "spa day" is progressing.
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  #27  
Old 04-08-2022, 05:25 PM
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Default 1920s Regal parlor full rebuild: Body breakdown, Step 2 update fixing top warping

The results are in and they are pretty much what I had expected, and that's a good thing. The top responded well to a dose of hot water to soften the wood and then four days in a compress to flatten out as much as possible. The photos show the before and after condition of the top in the vicinity of the sound hole where warping was the worst. Now that the hard work is done, the top will remain in the compress under light pressure and rest up until its time for top bracing.

Next post we'll dive into the neck and review how to prepare it for its new life.
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  #28  
Old 04-10-2022, 08:40 AM
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I have a candidate for a refresh. I am looking forward to your top bracing section.

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  #29  
Old 04-14-2022, 06:18 AM
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Default 1920s Regal parlor full rebuild: Lining replacement

I was planning on this thread being about the neck assembly but the new fretboard has not arrived yet so let's move on to the lining replacement instead. Here's an important consideration for replacing linings on a guitar rim that is misshapen from years of bad climate juju. The linings of a guitar not only give the top and back an ample, solid surface to attached to but also reinforce the shape of the rim as well. If you've ever held a guitar rim without it's linings then you know its very malleable and easy to form a shape other than the one you'd like it to take.

TIP: To avoid a misshapen rim from taking a shape that I don't want, I only replace one side of lining at a time. In this case I'm removing and replacing the top lining first and then, after the new top lining is in place, I'll remove and replace the back lining. The shape of the rim will remain in tact and I'll avoid more work come time to reglue the top and back to the rim.

Photo 1 shows the condition of original lining, which is in no way salvageable IMO. New mahogany lining will replace the old after all mating surfaces are cleaned, sanded and ready for glue/clamp.

Photo 2. The Exacto knife with sturdy blade should take the old lining off but I need to go slow so as to not risk cutting into the sides by mistake.

Photo 3. I use an 80 grit disc on the orbital shader to get as much dust, dirt and glue residue off as I can access and then hand-sand everywhere else to get where the sander won't go.

Photo 4. While the rim is easy to work on I always reinforce the neck block and end block while I'm at it. Both blocks on old parlors, and especially the end block, are prone to cracking when dropped so a quick overlay of mahogany layered opposite the grain on both is a good insurance policy against failure.

Photo 5. Once the rim is sanded but before the new lining is glued on I use my rotary tool with a mill end bit to scuff up the mating surface of the rim. By going with the rotation of the bit, this step does a great job of taking off any left over bits from the old lining and gives the new lining good surface to adhere to. Before I glue the new lining on I use this same bit to scuff up the glue surface if it as well.

Photo 6. Using my hodge podge of spring clamps, the new mahogany lining is aligned with the top edge of the rim and glue applied to both surfaces before clamping. I ensure the squeeze out is ample but not gushing and clean the top and side surfaces of excess glue as the clamping pressure starts to work. Once the glue cures on the top lining then I can remove the back lining and repeat the same process.


As soon as the new fretboard arrives I'll post my approach to upgrading the neck assembly.


.
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  #30  
Old 04-14-2022, 07:59 AM
Fathand Fathand is offline
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Have you ever used any kind of a mold to hold the rim in shape while attaching linings? Double thick cardboard inside the rim can work.
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