Official Luthiers Forum!

Was talking to a veteran repair friend in St Paul MN the other day. Watching him steam off a neck and noticed this. Went back home and immediately installed one. It's a fuel shut off valve to control steam so you can shut it off briefly while positioning and removing the needle. Looks to me like it could help minimize finish blushing etc. I am sure all you repair folks have been doing this for years!

IMG_8192 by Terence Kennedy, on Flickr

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

You figured it out before me.
thanks for sharing.

_________________
Say what you do, Do what you say.

Any concern about pressure safety with that system when you valve off the steam? I suspect your espresso maker has a pressure relief valve in it, but don't know for sure.

_________________
Jim Watts
http://jameswattsguitars.com

Is that a motorcycle valve or one from a model airplane?

_________________
"Act your age, not your shoe size" - Prince

It's a fuel shutoff valve from an auto parts store. For 1/4" fuel line which is what came on the StewMac needle assembly I got years ago. I think mainly for small engines.

I just rigged it up and need to try it out. When I steam off necks I usually leave the needle in a big pyrex pitcher steaming away and then pull it out and stick it in the hole for as long as seems necessary while wiggling the neck (which is in a vise) with the StewMac neck removal jig on. My friend did the same except he shut it off just before putting it in the hole and before removing it to avoid getting steam on the guitar. Once back in the pitcher it is opened. He has used his rig for many neck resets so I think it is safe.

I agree, leaving it closed for longer than a few seconds would be worrisome as far as pressure buildup. I have an old Mr Coffee espresso machine and I am not sure if it has a pressure relief valve.

I will report back after I have tried it out. Just wondering if anyone else had tried something similar.

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

Sounds good, I just didn’t want it to be a “I should have thought about that” moment.

_________________
Jim Watts
http://jameswattsguitars.com

Having a way to start and stop the steam is certainly helpful. If you don’t already have an espresso machine, pressure cooker etc then these are worth a look too:



Trigger operation for the steam, pressure relief valve etc. The usual size of auto hose clamps right onto the nozzle.


Sent from my iPhone using Tapatalk

Low pressure steam (15 psi or so) so no PSV required if your hoses, valve and components are rated. High pressure steam is a different animal. Anyone want to discuss critical or super critical steam?

That’s what I use. Lots better than my old expresso maker.


Steve

_________________
Steve Smith
"Music is what feelings sound like"

No we use the "Hesh here hold this outside the window for a minute" method so this is very welcome here.

Great idea, thanks Terry!!!

Our neck steamer had a similar all-metal petcock valve installed inline, but we used a piece of silicon tubing over the handle to prevent those Yellowstone-like brandings during those rare instances when bare hands were present.

Not sure if the espresso machine neck steamer has been used in the last six or seven years at Greenridge or other local shops here that do reset work beyond truly vintage guitars where the slightly larger access holes might be somewhat visible in lighter BRW boards outside the edges of the frets. I borrowed the HeatStick setup last year and did a few 1980's Yamaha flattop neck resets for a local non-profit (the necks pop off without damage once the epoxy gets enough heat in it... thermoplastic glues!)... no drama with epoxied-in-place necks beyond having to make up some 5/32" plugs for the fretboard holes. When I returned it, I was press-ganged into a marathon session of Guild F-50 and Gibson J-45/J-50 necks... went even faster than the Yamahas, and no worry about either steaming the neck block out or finish touch-up. Greenridge is using wire-sized cobalt aircraft drills which generate smaller holes and plugs... will have to ask them about which size bit they use.

To be fair, we did have issues with the initial version of the HeatStick for digital Wellers, but the current stock setup with a digital soldering station as the base component has been durable in service. Given the advantages of the HeatStick, I'd expect steamers to eventually go the way of the method used prior to that - the barbarous 'cut off fretboard/steam dovetail directly.'

_________________
For the times they are a changin'

- Bob Dylan

Woodie I bought a heat stick a while back and besides the big hole it seemed like it took an eternity to work. Much longer than advertised. I was using the Solomon digital soldering station and settings recommended in the instructions. I was kind of underwhelmed.

Would you mind sharing your technique? Thanks!

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

I am interested in how hot the heat stick probe has to get, in order to get the glue to release in the joint. I have a shop made version, but I am not sure if the probe is getting hot enough. It will char wood 3" out from the soldering iron, so I would think that would be hot enough. I tried it on one beater, as a trial, and the neck came out.

I practiced plugging the 5/32" hole on a Madagascar fret board scrap. I used a random scrap of BRW, from the scrap box, and sized it with my drill sizing template. This is using end grain for the plug, but it still came out fairly well. That is a StewMac medium acoustic fret, which is .085" wide.

Sorry, but I listed the pictures in reverse order, and am too lazy to reverse them:>)

Well I fired up the Mister Coffee today and the valve worked well. No leakage. Maximum close time was about 30-40 sec without incident which should be plenty of time to get the needle in or out. Still interested in hearing about folk’s heat stick experiences.

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

These things https://smile.amazon.com/GOCHANGE-Elect ... 102&sr=8-8 (many different brands available—some with temp control) are available quite cheaply. I bought a couple to play with but I haven’t had to do a reset since I got them. The ones I got have a temperature control knob. They get hot pretty quickly and don’t need a big hole. If anyone experiments with them, please report back.

Dr. Kennedy:

In my experience, the HeatStick method will always take a few minutes longer than steam due to the slower heat transfer, but that seems to me to be a fair trade in avoiding the steam-related damage (e.g., blush, softening, and in extreme cases blistering) with the attendant need to repair that damage. We found that the following minimized the additional time required:

- Use the maximum temperature setting on the digital temperature control unit (we ignored the recommendations from SM after finding them to be suspect). Keeping the temp max'd out makes it more likely that wood will be charred if the task is forgotten, but with regular swaps between bass and treble holes and judicious applications of water using a disposable pipette, we did not see any issues.

- A moderate amount of moisture (about 1/2 ml) via disposable pipette should be added to the joint every time the HeatStick is moved between bass and treble sides - this maximizes heat transfer and utilizes the excess energy available from the digital controller to vaporize that added water. There should be very little evidence of steam generation out of the holes beyond the initial burst as the rod is cyclically inserted in each (this is somewhat repetitive, but keeps the heating even between bass and treble sides... we generally saw best results with swap between bass and treble side holes every 1-2 minutes). No evidence of water leakage should be seen from the heel... if that occurs, reduce the amount of water added on each cycle.

- The rod must be kept clean... heavy corrosion or cooked-on glue residue is the enemy of good heat transfer. We used a bronze foil pad of the type used to clean tinned soldering iron tips, and ran that up and down the copper heating rod after every 3-4 cycles between bass and treble holes. We also cleaned and buffed the copper rod after use but before storage to knock off any stubborn glue and corrosion. Adhesive - especially Titebond residue - may act to bind the rod in the opening if the rotation between holes is ignored... a quarter twist with pliers applied at the top of the rod will allow extraction without scoring the important part of the tool.

The nominal hole size in the directions and for the bit provided is 5/32" (0.156"), but a #29 wire drill at 0.136" has plenty of clearance for the 0.125" copper rod. This reduces the size of the plug needed by about 0.02". The last time I did this work, we were using jobber and 6" length cobalt aircraft drill bits, with the 6" bit about $3 from Amazon. We had a pack of shorter #29 bits that were used with the disk sander to finish face-grain plugs... the blanks are marked on both face surfaces with pencil so that grain may be more easily aligned, then medium CA does the job of holding blank to bit as it is spun against a fresh sanding disk. I recommend against using end grain plugs, despite how easy they may be to fabricate.... grain- and color-matched plus do a nice job of hiding even on lighter rosewoods if tightly fitted.

The attached shot of a Guild 2005 F-50's 15th fret plugs shows how inconspicuous that repair can be on ebony... only the bass side plug on the nut side of the 15th fret is noticeable, and only because the final steel wool work and waxing of the board was not yet accomplished. If memory serves, I did these plugs with a 5/32" bit, so these extend nearly 0.030" to either side of the 95 x 47 fret wire.



Adding a second unit to the mix would get total wattage up to 90 (the hand piece on the SM digital soldering station is rated at 45W), but at just over $170 each at discount, that is pricey compared to a garage sale espresso machine and needle/hose/etc. Greenridge did have two units (two is one; one is none per Mr. Stock), but one somehow ended up in my shop... next time I get back over that way, I will see what dueling HeatSticks can do to keep things moving.

_________________
For the times they are a changin'

- Bob Dylan

Do you have any info on how hot the probe gets when it is on the highest setting?

I have not tried the SM heatstick but have used hot wire foam cutters of this type. Two at once works pretty fast on a Martin style neck and they are thin to boot. A Gibson I’ve used them on took a lot longer - there was a mountain of glue between tenon cheeks and sides that took time to soften.

Woodie, thanks for the detailed information. I have also found that the dry heat method does make previously “unresettable” necks removable. My initial trial victims when I first started messing with dry heat were a recent Chinese Fender dread and a 70s Japanese epoxy nightmare and both were off in under 10 minutes of heating.

According to the manufacturer, 900 deg F/480 deg C, but I suspect that is in open air after full warmup as measured at the temp sensor in the hand piece. The copper tip will be a bit cooler than that, but I have never take a direct measurement. Much like a bending blanket, it seems as though the goal in removing a neck is to get the adhered surfaces in the dovetail and socket hot enough to liquify the glue as quickly as possible. For a steamer, the phase change from vapor to liquid dumps all all that heat energy into the wood to quickly warm the joint. For the HeatStick, the heat energy available from the hand piece element trying to maintain a 900 deg F temp provides that excess, with some help from both trapped water already in the wood and the periodic addition of small amounts of additional water via pipette.

In summary: it seems as though temperature is not really the issue, although a glowing mini light saber seems like it is something to be avoided. What matters seems to be the ability to bring the operative parts of the joint up above the transition temperature QUICKLY for the adhesive used. Lower wattage systems will take longer to heat the joint, which means that the entire area can become heat soaked, unintentially loosening other joints such as the sides and plate joint with the neck block.

_________________
For the times they are a changin'

- Bob Dylan

I've been using two diy heat sticks and have had pretty good results. One of the heat sticks was made to fit my old Weller soldering iron and the other heat stick fits an even older lacquer stick application iron.

To make wood plugs I glue a small piece of rosewood or ebony face grain wood onto a scrap piece of pine and turn it in a Taig lathe.