Official Luthiers Forum!

Hi

Sorry for the amateur question but havnt a clue about sealing and finishing the guitar
Can someone tell me what they use to seal the soundboard with before trimming and cutting binding channel etc

Soundboard is alpine spruce and i am looking to keep its light colour and an end finish that is matt look all over

Thankyou

Shellac is all I've ever used, 2 lb cut, or 2/3 coats of 1 lb cut, just wiped on with a paper towel or lint free cotton cloth.
Use same in rosette area before cutting the recesses, and again inside them before gluing in the components.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Thanks colin.. tried searching ebay for shellac and all i can find is nail polish lol..
Is that what you use for final finish as well

No, I'm only using it here to bind the softwood fibers to help get cleaner cuts with the router.
It generally gets sanded off while leveling the bindings and rosettes.
Finishing is a different ball game, and I'm no expert
Try looking for Zinsser SealCoat Sanding Sealer, (basically a 2lb cut shellac)
Or you can make up your own shellac as you need to.
I remember you are in UK --
I think 1L is smallest available, so making your own is much more economic, buying refined wax free shellac (I use blond) and using meths or isopropyl alcohol as a solvent. Both available from the bay.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Thanks colin
Just ordered a uk version of it
And will give it a try
Do you tend to use it on the whole guitar (sides/back/neck) when your sanding down

Shellac here too and I also like the Zinnser dewaxed stuff for utility purposes around the shop.

Another benefit of using some shellac meaning enough to cover the binding channels and where the tape, if you use tape for the binding process is that shellac will help prevent lifting fibers when the tape is removed after the glue that one uses for binding dries. Gently warming the tape in advance of where you are pulling off the tape also helps to soften the adhesive and prevent lifting fibers as well.

Here's a pic of how I bind and use shellac to help prevent lifting fibers when removing tape - works great for me.

I'm very new at this also, but have discovered early on how sealing really helps when cutting channels and removing tape as well. Just to be quick and easy, I use Zinnser's in the spray can just to hit where the tape will be. I don't see on the can anywhere that it is their de-waxed version, but haven't had any issues with finishing later on. I do sand/scrape most of it off long before finishing anyway.

@Hesh--just curious, when you use tape for binding, do you also wrap with latex bands or anything, or just rely on the tape?

I just use rattle can lacquer. It dries fast, is easy to deal with and gets sanded or scraped off when you are done with the bindings and rosette. And hobby or hardware store will have it.

Shane

_________________
Canada

I kind of forgot about the shellac helping with pulling the tape off thing.
Regarding the whole guitar thing, I don't see any point in having shellac when you sand down, it just gums up the abrasive quickly as you're sanding it off.
Having said that, I did find a light coat all over the soundboard helps to stop ingrain dirt/stuff from handling into the wood as I am working with the box.
I have generally used it all over after pore filling and sanding back, partly to help see any scratches and dents I've inflicted, but mostly as insurance for my (sometimes unconventional) finishing to help ensure adhesion of the finish itself to whatever I'm using to pore fill, be it ZePoxy/oil based/egg white.
Slellac has a reputation for most finishes sticking well to it. I've used a couple of water based, Tru-oil and Liberon finishing oil with no adhesion problems so far.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Howdy David - Tape works fine for me because I fit my bindings very well in advance of installing them. I've seen the pics and read the posts of folks using rope on the box, using a thousand rubber bands, etc. and never really understood why one would not simply fit the bindings well first and completely negate the need for any horsepower to clamp them in place.

A common mistake that newer builders make that I made too was using very thick, very tall bindings combined with a binding ledge channel cutting solution that does not cut a uniform channel all the way around the box.

If you make your bindings thinner, less tall, prebend them in the Fox bender, break the inside edge so they snug up in the channel well, and cut uniform channels very little clamping force is actually required.

Here is a pic of a test fitting and you can see that it required very little tape to get things close....

Evening, Hesh

When do you actually get any work done? You are always here!!!

Cheers! M

Thanks for the tips. .. would be lost without the help on here... will ask about pore fill when i get there

Take another real close look at that spray can -- pretty sure you'll find specific mention of "de waxed". (Don't have ready access to can myself at the moment, but I remember this question coming up before.)

Slightly off topic...

Another trick for removing binding tape is a drop of denatured alcohol. Capillary action causes the glue to release on contact. Not sure what It would do on a shellac sealed top.

Best, M

Just wanted to add something really quick to all of the great info you've already received. I agree that the Zinser Seal Coat is a great utility shellac for around the shop. You mentioned that you wanted to preserve the light color of the Alpine spruce top and Liberon's "Special Pale French Pollish" is about the lightest I've found. I have used it on a couple of really light cored tops for that very same reason. I'm in the US, but here is a link to a UK supplier.

http://www.axminster.co.uk/liberon-spec ... nch-polish

_________________
sweat the small stuff.

Thanks Heath
Good tip
Sorry to be a bit clueless can i use this for a finishing coat..if so whats the process you use ..really want to keep the natural look of the wood with a matt finish

Hey Michael - I'm wired everywhere I am including my car with full IPhone integration and a 7" display.... I'm also pretty well known as a multi-tasker capable of fixing Les Pauls and D-28s at the very same time.... and still have enough bandwidth to post on the OLF and irritate folks....

You most definitely can use it as a finishing coat, but you'll have to get some advice from some of the more experienced folks around here on French polishing. I generally just use it a seal coat. I believe a matte finish will require a specific finishing prouduct, as most finishes will pollish up with use over time anyway. Finishing hasn't been my strongpoint in guitar building, thus far. Sorry I couldn't be of more help!

_________________
sweat the small stuff.

You are long winded, but never annoying!

There are so many great modern solvent coatings (some of which are crystal clear) I retired shellac decades ago. Choosing to forgo all the tradition and associated hassles. As far as pre-treating surfaces prior to routing or trim installation -- I never do that, economy of effort, I have not had or seen the need. Sharp tools/bits are the key, of course proper routing patterns and a hair dyer to release the tape. Regardless of our opinion of the final products fit and finish of the major makers is pretty darn good, so I figure if Martin, Taylor, Yamaha etc. can each make a 200 or more units a day without pre-treat coatings perhaps I need to see how they do it and some other things as well. In my view "Hand Made" does not have equate to made with difficulty. So the point of my blab is -- sharp bits, good process and a little skills practice are the best insurance for a nice trim job.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

I suppose labelling may vary in different markets -- mine was purchased in New Zealand. Unfortunately, zinnser wouldn't be able to put all product data on a rattle can, but it IS available here : http://www.menards.com/main/store/20090 ... 408TDS.pdf Look carefully, but it IS there. I should think aerosol shellac would almost have to be dewaxed (100% wax free) to prevent clogging of the nozzle.