I have a neck that shall be seperated from a body (Flatiron A) for replacement. I just learned of the heat stick and it seems like an attractive option. Is it?
I have a neck that shall be seperated from a body (Flatiron A) for replacement. I just learned of the heat stick and it seems like an attractive option. Is it?
I'm not sure but I vaguely remember reading that Flatiron used bolt on necks... What kind of neck joint does your mandolin have?
Steaming can be messy but I've seen badly scorched wood with the stick.
If you remember the fretboard first, you'll have good access to neck joint so you cane direct the steam more effectively in several spots unlike the blind steaming of guitar neck.
Adrian
I can't speak for all experienced repair people, but those of us who have been steaming necks out of instruments for decades seem to be mostly unimpressed with the heat stick. Of course those of us who have been steaming necks out of instruments for decades can be set in our ways, and also we've developed our technique with steam needles to get good results.
John Hamlett
www.hamlettinstruments.com
There is a repair tech on YouTube, twoodfrd who has a few videos where he uses them and talks about the pluses and minus's of them. I believe he continues to use the technology but uses a smaller set of rods and still has to use steam on occasion.
Certainly haven’t used this, but am much impressed with the cost! An 1/8” chrome-copper (it’s stiffer than pure copper) rod in small quantity costs about $7 for half a foot, from an expensive supplier! Low-volume product woes, so if one wanted to experiment with this or related techniques; flat blades, etc. there’s not much to think about. Their video involves drilling through a fret kerf in a specific direction, which depends on some specific (guitar) construction. I think that mandolins are varied enough to make a shortcut inapplicable unless the typical luthier, like an interventional radiologist, has a handy tabletop CAT scanner for guidance.
I found the long drill bit to be useful for stuff:-)
Richard Hutchings
I haven't used the heat stick, but a couple of times I have tried my 1" x 5" heat blanket, which is also a source of dry heat, and which is my go-to for removing guitar bridges, on exposed dovetail joints. In one case it worked, in the other it did not. The funny thing was that both of the joints were put together with hide glue. At least some joints need steam or wet heat to open up.
And yes, Stew-mac has gotten a lot more pricey since they changed ownership.
Hide glue is mostly unaffected by heat alone and really does need some moisture to change state back to a softened gel or liquid where it can be more easily released. I did an experiment to see what effect heating dry hide glue would have. Dry hide glue granules where set on an Aluminum bar, which was heated with on a hot plate. I heated things up and watched the temperature with a bi-metallic thermometer.
This image at 150 degrees, still looks unchanged.
Now at 300 degrees, whatever moister that was in the hide glue began to leave the still mostly unaffected granules and they started popping bit.
I took it to 400 degrees and it started smoking. At this temperature, wood will be burning as well. You can see there was definitely NO melting to 400 degrees, although the granules do look a bit worse for the wear.
You really do need some hydration with hide glue when using the hot rod method but will end up with more heat than necessary this way getting it to release. The few applications I used a hot rod for left a burn ring around the rod hole.
Sucker for a hard luck case
Maybe try it on a piece of wood. I've read on other forums or was it FB, that wood has enough moisture in it to help soften the glue. Sounds like hogwash but ... I led them straight to Frank Fords test and they still won't buy it because they have somehow had success separating parts.
Richard Hutchings
HHG won't melt with dry heat but the adhesion and cohesion of the glue itself weakens when hot.
Moisture will remelt the glue but the wood will get weaker with moisture and you're more likely to pull splinters of wood. Dry removal of HHG bridge can sound drastic but it works.
Violin restorers often use drops of alcohol into the joint. The alcohol makes the dry HHG brittle for easier removal. You have to be careful not to get the alcohol on varnish.
Adrian
Alcohol can be effective for intentionally weak joints such as the join between a violin top and ribs. I have my doubts about it's effectiveness on a strong joint, such as a guitar bridge or neck joint. I have heard frustration from a few violin repairers that have tried alcohol for dry fingerboard removal, given up and got out their hot knives with a bit of water or steam rigs.
Yes, heat does degrade HHG, as can be seen in my last image but you need 300 or more degrees to get there.
If there’s a deficit with a (dry) soldering iron heated rod, it would mostly be the very much non-uniform temperature in use. Something like puttiing the frying pan half off the burner: even with a copper bottom there’s going to be a gradient, and the omelet isn’t going to cook evenly. Since with a soldering iron the starting temperature may be 500 F+, and the end of a long rod (depending on some very variable stuff related to the thermal conditions at all points in the hole, will be much lower.
So can something like this (a dry, thin heater) made with a similar uniformity to steam? I think so, but it requires a fair amount of complications. In my work, I’ve used small diameter resistance heaters that might work, but uniformity is going to require a circulating fluid… maybe if NASA wants to get into lutherie.
The heat stick is an attempt to avoid the moisture that conventional steam releasing introduces into a neck joint, but not every proposed solution to a problem is a good idea.
When a neck joint is opened, the various surfaces being freed up are not exact locations that can be pinpointed with surgical accuracy. Steam allows the heat to get everywhere you need it to go, without the risk of the exact source of the heat creating a burn hazard. The introduction of steam and the resulting boiling water may not be something that you necessarily "want" near a guitar, but the joint reliably dries out again afterwards. Anything that can cause a guitar's wood to actually burn (which it will at dry temperatures) has to be viewed with some caution.
But Amsterdam was always good for grieving
And London never fails to leave me blue
And Paris never was my kinda town
So I walked around with the Ft. Worth Blues
After looking at their video I see the guy is injecting water into the hole so they actually don't avoid steam and water in the joint. And that ugly burned scar in the joint... I wonder how charred the hole in fingerboard got.
Adrian
After using steam for about five year's worth of neck removals, for resets, I switched to the Heat Stick, to avoid steam damage. Yes, any finish damage from steaming is usually not bad, and can be reversed...but sometimes, with a recalcitrant neck joint, there is lacquer damage requiring touch-up. I have used the Heat Stick for several years now, with no steam damage. Kudos to those who are able to use steam with consistently good results, but the HS works for me, and is especially helpful on almost anything but a Martin(which usually release fairly quickly). I do use a pipette, to drop water in the hole, quite often, but it's not yet resulted in any finish or wood problem. I avoid scorching the fingerboard by keeping the heat setting below 340 degrees. Yesterday, I had to remove the neck on a beat 1948/49 Gibson LG2. When the joint finally released completely(after about 40 minutes: yup, it takes longer than steam), surprise!! The factory had assembled the guitar, with the top over the dovetail. This situation, with steam, could have been a big mess, but not with the HS. Again, if steam works for you, great. For me, and perhaps others, the HS is a good alternative.
Checked on availability of very small diameter cased tubular resistance heaters- lots of sources, down to 0.040” diameter, but I also think it’s a poor application. I imagine some folks have used hot-wire devices for things like fingerboards where both sides are accessible.
I've had to remove one of those. It was a mess in many ways (crazy construction method, but I think I know why they did that sometimes), but my steam needle did no more damage than usual. (Partly, I figured out what the problem was early in the process so that I could 'recalculate' before damage was done.)
So anyway, there is no substitute for experience sometimes, and surprises like this are not necessarily a big mess when steaming.
John Hamlett
www.hamlettinstruments.com
I had them occur from the late 30's, early '70's, and now late '40's('48?). No rhyme or reason to it: some are that way, others not. I also just removed a neck from a '49 Gibson SJ, which dod not have the top over the dovetail.
You can add a c. 1944 J-45 to the list. A friend of mine has stated that he has seen a covered dovetail on at least one Martin, but did not mention the period or model.
The way I understand it, covered dovetails have been seen on quite a few old Gibsons. And no, there doesn't seem to be any pattern for their occurence.
The last Gibson neck that I pulled was on a c. 1937 Roy Smeck. That one did not have a covered dovetail and came off quite easily.
I think the covered dovetails are factory re-tops. Something happened to the top late in the manufacturing process so they replaced it without removing the neck. There are several clues that point toward this as an explanation.
1. A shim under the fingerboard extension. This one was spruce with the edges painted black so it was invisible, and it was my first clue that something was "funny" about this one.
When trying to separate the extender from the top it felt spongy like the 'board and the top were not really separating. Turned out my putty knife was going into the spruce shim.
2. With the shim removed it revealed little elevated binding bits that were under the fingerboard extension.
If the top was ruined and replaced, imagine some kind of cutter that removed the top and part of the rim and linings, dovetail tenon and all. Then a new top was installed leaving the top lower than the plane of the neck. A shim was added to restore the level under the extender, binding applied to the top and trimmed, then the fingerboard glued on. That process would result in bindings and shim like this one that I encountered and would explain the apparent randomness of covered dovetails.
It would also contribute to thread drift here apparently...
By the way, if this one ever needs another neck reset in any of our lifetimes, fear not. I used a rosewood shim (to match the fingerboard and left the dovetail open.
John Hamlett
www.hamlettinstruments.com
I just gave the heat stick a try. Been using a converted cappuccino machine to make steam for years. Did a test on a junker parlor guitar and it worked well. I then moved on to the job of a 1948 D28 Martin. Right off, I don't like the larger hole needed drilled into the fret slot. I probably wouldn't use it on a BRW FB.
After drilling and inserting the rod, I set the soldering iron to around 600 degrees F. I added water from a syringe within the first minute. About 3 minutes, I added more water. I started to tighten the wing nuts on my jig around 4 minutes and the neck popped loose. No steam damage, and I was able to start working on the dovetail within a few hours instead of waiting a day or two for things to dry out from steam.
The LG2, which I mentioned earlier, also had that oddball spruce shim under the fingerboard extension. I've not seen that before. Your theory about a factory retop may well be right.
I forget where now but I ran across another discussion on the heat stick, where a guy was using two rods for neck removal. That would certainly help to heat things up more evenly. Obviously, it's twice the investment for proper soldering rigs but worth while if you do a lot of neck resets. I'm pretty sure this person was making his own rods, definitely some saving to make your own. I have been drilling two holes and alternating the rod between them. That helps but two rods would be better.
The size of hole was an issue for me. The supplied drill bit in the Stewmac kit is a bit oversize, a #27 (.144"). First time out with this rig, I made holes the same diameter as the rod, 1/8" holes. I soon found out that you do actually need that hole diameter a bit larger than the rod. Glue sticks to the hot rod and makes it very difficult to get the rod in and out and increases the risk of ripping the guts out of the hand piece.
Sucker for a hard luck case
m pretty sure this person was making his own rods, definitely some saving to make your own. I have been drilling two holes and alternating the rod between them. That helps but two rods would be better.”
If you want, use plain copper rods, not brass or iron. The alloy of the S-M only adds a little stiffness, has no other virtue. Many of the good soldering irons, like Weller, use threaded tips that may be bigger than 1/8”, but if you have tools, you can thread the copper and make an tapped insert for whatever iron you have. No machining, really. Also, the S-M version uses low-cost 40W pencil irons, so anything +/- should be ok, or if too hot, use a lamp dimmer.
I suppose you could also make ‘non-stick’ rods with a suitable coating.
Having so far only detached one neck (brute force with a heat gun on a low-value instrument), I don’t have experience, but if I did want to make a better version of a rod heater, I’d start with uniform temperature rather than an extended soldering iron tip. (See #17).
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