Official Luthiers Forum!

   I've got an almost full quart of KTM-9 that is about two years old. I brushed some on a scrap and it seemed to dry okay. Anyone know if it is safe to use, or am I looking for trouble later?

   Thanks, Paul Harrell

I have only been using it a year, but like most finishes it is dependent on temp changes it has gone through. My guess is that if it has been sealed well and stored in a dry location it is likly to be ok.

I recently used some KTM9 that was at least 2 years old. It was in a can
that was at least 3/4 empty. It sprayed just as well as ever and dried just
as quickly and clear as ever. The temperature in my shop stays fairly cool
and in the winter can get down to 58 degrees when I'm not in it, so
storing in a cool location probably extends its life. I'm sure Grafton
Coatings publishes a shelf life to cover their warranty, but it's probably
considerably longer than what they publish. I wouldn't worry too much
about using it, but try a sample and see how it dries. If it dries quickly
and can be sanded in a day or 2, go for it.
Craig

KTM-9 will last at least 1 year if not 2-3.

Reasoning is because everyone handles and stores product differently.

Once the can is sealed, stored in a dry atmosphere and temperature above 50ish, it should be fine. Would recommend that if it is stored in a cooler room, that is sit at ambient temperature allowing the product to warm up to room temp before applying.

The product will pass (what we call) 1-2 freeze/thaw cycles.

Overtime (over 1-2 years) we do see the product slightly thicken due to the resins reacting. A quick fix of no more than 3% water to product weight being used, will fix it.

If you ever open a can and a sulfuric smell is there, there’s a good chance the product has gone bad - which could mean it wasn’t stored properly (lid partially open, etc.).

matt
Grafted Coatings, Inc.

_________________
Matthew Lawrence
R&D Technical Support
Grafted Coatings Inc.
www.graftedcoatings.com

HI Matt!
Welcome back to the OLF!


Lance

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Lance@LuthiersForum.com

Thanks,

I kept forgetting my user/pass so I just created a new one and wrote it down.

Congrats on how the board is working and the design of it.

matt

_________________
Matthew Lawrence
R&D Technical Support
Grafted Coatings Inc.
www.graftedcoatings.com

[QUOTE=KTM9] Thanks,

I kept forgetting my user/pass so I just created a new one and wrote it down.

Congrats on how the board is working and the design of it.

matt[/QUOTE]

Matt I love your product. There is one thing that needs improved. I would be real helpful if it was self applying

Welcome, Matt (KTM-9). Many of us know you intimately!
Craig

Thanks for the information everyone, sounds like it's safe to use what I have.
                        Paul Harrell

Matt...Thanks so much for posting. It gives us great confidence in your product to find you chiming in.

_________________
JJ
Napa, CA
http://www.DonohueGuitars.com

Happy to help out with questions anytime. Its great to hear so many of you are having good experiences with our KTM-9.

As for MichaelP, I will see what I can do..hah

A question for you: We know various luthiers cut KTM-9 with denatured alcohol - we recommend destilled water.

Any of you try both and see different results? What results do you see when you add denatured alcohol to KTM-9 verses without. Im taking it, burn-in effect.

Out of the can, KTM-9 is set for spraying, brushing, wiping on, etc.

We always take in the feedback for learning purposes and possible imporvements.

thanks,

matt

_________________
Matthew Lawrence
R&D Technical Support
Grafted Coatings Inc.
www.graftedcoatings.com

Matt, I spray a very, very light coat of DA before the first coat the second day, if coating goes more than one day. I allow it to flash off then start that days coating. I find I get better burn in this way. It seems to soften the day befors top surface just enough. but i don't thin my mix with DA. I too use Dist. H2O if I have a need to thinMichaelP38660.3717592593

We recommend DA between coats as to neutralize the surface from any material left behind from sanding, dust if sat for a while, etc which could cause intercoat adhesion issues, fisheyes, etc...

It will also slightly soften the surface helping with the so-called burnin.

matt

_________________
Matthew Lawrence
R&D Technical Support
Grafted Coatings Inc.
www.graftedcoatings.com