Official Luthiers Forum!

In your opinion, which is better for fretboard extension removal, the Stew Mac Bridge Heater and Fingerboard Iron or the LMI Repair blanket for fingerboard extension?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I have both, I like the blanket more; although I have used the bridge iron as the weight over the blanket. Do you have the LMI controller? Their blankets have the funny plug that fits in their controller.

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http://www.Harvestmoonguitars.com

Neither.... Save yourself some money and get a 250w heat lamp and fixture and make a protective shield(s).

The same lamp will also remove bridges as well.

I didn't think about the connector... hummm... Hesh, (or others) what would be a good heat shield for the top while using a heat lamp? ...cardboard? ...foam core?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

Steve here is a good thread where I posted a pic (sorry the pic is sideways....) of some of our many shields and I believe in the narrative of some of the posts how to make the shields is discussed too:

http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=43474&p=575093&hilit=shield#p575093

We have blankets and the Stew-Mac thing... but never use them favoring a heat lamp and shields.

Hesh,
In that thread you said. "A heat lamp is instant heat especially when positioned perhaps 1/2" from bridge to bulb." Wow, that seems close... Is that what I should do? I figured it would be held maybe 6-12" from the bridge (or fretboard extension in this case). Should I place the bulb that close, that is 1/2"?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

....

Yes indeed..!!
Tom

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A person who has never made a mistake has never made anything!!!

I get my blankets from Watco. I've got several different sizes and just put my own plugs on em. I have lots of protective cauls just made from cardboard and aluminum foil, but my newer ones are leather with foil. Both work fine.


Ken Jones
Mountain Song Guitars

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Mountain Song Guitars www.mountainsongguitars.com

I found the heating iron pretty worthless and use the blanket shown weighted down by a cloth bag filled with lead shot. That has worked fine for me.


I like the light, I 'm sure it works great. Just have not tried it.

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

I've used irons, blankets, even custom shaped blocks with heating elements installed. I still go back to the old heat lamp for bridges and fingerboard extensions.

The key point is that with blocks and blankets you are relying on heat transfer through direct contact or ambient heat where any gaps exist in the fit, and unless you make a perfectly mated caul or block for each individual job, there will be some combination of the two very different rates of heat transfer through the surface. With light on the other hand, heat is generated directly in the material as the light makes contact, and in practical terms the consistency of heating rests solely on consistency of illumination.

For protecting surrounding surfaces, aluminum foil and metal HVAC tape over a piece of cardboard do a perfect job of reflecting light to prevent heat from being generated to begin with, and cardboard will insulate what little may exist. I do typically cut the guard a bit wide, then span the gap with a bit of HVAC tape to maybe 1/8" in over the extension or bridge.

The weak spots of the lamp are few. One is that with the cardboard/foil heat shield in place, moisture can steam out and get trapped around the perimeter, but this is rarely an issue. Lately I've taken to cutting the cardboard wider around the piece and spanning the larger air gap with metal tape to allow better ventilation, but this is more an abstract "improvement" than one borne by necessity, as I've not had any problems caused by this.

As to distance, I typically set the bulb directly on the wood, moving it around every 30 seconds or so. Apply heat fast as you can without scorching the wood, and you can raise the temperature of the glue joint before heat has a chance to migrate beyond to areas you don't intend to heat. Heating slowly may seem more safe, but this slow application can induce a less focused heat and allow it to migrate further before your intended joint reaches critical temp.

Still, there's a learning curve, and the more intense the heat application, the less room for error there is in timing. Half inch to an inch is a good starting point. By the time you reach several inches though, the heat application can be too slow in my opinion, and allow for heat to spread further than desired.

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Eschew obfuscation, espouse elucidation.

I use a heat lamp that is placed about 4" from the surface.
Aluminum foil on corrugated cardboard or thin rigid foam certainly works as a heat shield, but I have found that white corrugated cardboard works just fine.
IMHO, the shield should overlap the edge of the fingerboard about 1/8". This helps keep the heat away from the finish.
To check the temperature, I use a small brush to put water on the surface. When it starts to sizzle, it is getting hot enough.
This normally takes about 5 minutes, more or less.
The darker the surface, the faster it heats up. In that regard, ebony usually heats quicker than rosewood.

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John

Okay - It looks like the prevaling opinion is to go with a heat lamp. So, I should get a 250 watt heat lamp... It sounds like I need to have the lamp about 1/2" from the fretboard for about one minute (or a little more after checking to see if it has loosened) to heat it up fast and generate excessive heat that could impact other glue joints. What type of reflector is recommended? Is there a recommended set-up for this procedure?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I have been using this:
Cheap, works well and you probably already have it.

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Greg
http://garibaldiinstruments.com/

I have the little fretboard heater....never use it. I have used my fretboard heating blanket....works great. I have used one of my wife's irons...works ok, but she wouldn't take it back after I got a little burned resin on it. I have used heat lamps from 150 to 250 watts and they are definitely the best way, using the ultra high tech tin foil/card board heat shield.

Just be careful on some of the older guitars. If the fretboard markers are mother of toilet seat, they will cook to a curly crisp very quickly. Don't ask me how I know that.

Good luck,

James

Steve make a shield out of cardboard and cover it with quality foil, shiny side out. Cover any gaps with the shiny HVAC tape. I typically heat for about a minute and I might even see some smoke and smell something rather unpleasant.... then I remove the shield, turn off the heat lamp and start feeling around with my pallet knives. What I am looking for is a gummy feeling where I can make progress with the pallet knives with some pressure but never forcing anything. Working the knives back and forth can cut through the glue layer too once it's soft enough to feel gummy. It's not uncommon after this first check to put the shield back in place and reheat again for perhaps a minute or less. It's much more a function of feeling that gummy feeling than any set amount of time.

When you get a heat lamp try to get the smallest fixture that you can find too like a say a 8" one instead of the 12" ones that are common. This lets you focus more heat where you want and less where you don't want.

If the board is BRW by chance don't worry if oils come to the surface, a little smoke happens, and it stinks.... that's par for the course and not indicative of any problem. And if you have any MOTS dots as mentioned above cover them with one or two layers of the HVAC tape.

Remember too what kind of neck joint you have to avoid attempting to use the knives to separate where the board is glued to either the dovetail or tenon.

Thanks Hesh. You may have seen this guitar in the posts. It has a padauk fingerboard and has gold MOP dots (I don't usually put them in that far down - Dang it, I did this time). Should I put some kind of protective cover on the board - you suggested HVAC tape (available in the home store?). I don't want to scorch the padauk... BTW - M&T neck joint...

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com