Ktm-9

[bassman]

After initial testing of KTM-9, I am very pleased by the results. I used it on a piece of mahogany with syst. 3 epoxy as the grain filler and "grain popper". Brushing it on left me with a bit more leveling to do, and some extremely fine (smaller than pinpoint) divits from air bubbles. I buffed it up to a very high gloss. The finish has great depth and clarity- aside from the tiny air bubble divits (which I will find out how to avoid)- it looks damn sweet. I used the links on LMII to both Mike Doolin's and John Grevens tutorials as a starting point- extremely helpful. As for the hardness- I will have to wait for it to fully cure before I can determine that. People who have seen the testing piece on laying my dining room table have commented, without prodding or even being directed to it ("Wow, look at that finish-it's beautiful"). When it is more fully cured I will post results of its hardness. Feel free to ask me questions.

[johnsilver]

Thanks for doing this Bassman. I am interested in KTM-9 from LMIs catalog, so really interested in your experiences as you progress.

[mledbetter]

Me too. I was actually getting ready to order some. I will spray, but i'm anxious to see how others projects work out. Should it work fine with other grain fillers? or is it best to stick with the epoxy that LMI recommends?

[jer7440]

Have any pics of your sample?

[bassman]

I will post some pics of the sample sometime pretty soon.

I would definately use the epoxy as the grain filler, while effectively filling deep pores very quickly it also adds a bunch of depth to the grain. It also serves to make the overall finish harder and more dent resistant. Other fillers would probable be okay- but being it is such a new product and not much info on it I will stick with what has been suggested for now. I personally emailed Mike Dooline with some further questions and he promptly replied- you might do the same if you have some questions that he and Jon Greven dont refer to in their tutorials.

[mledbetter]

I already have. Very cool guy (Doolin) approachable and answered my questions. I'm going to order some in a few days.. Still cutting on the body and neck..

[bassman]

Here is something you might want to know... (LOOK AT CORRESPONDENCE BELOW)But everyday the finish seems to be getting harder- definitely a good thing. I have decided to wait a bit longer before I start putting this stuff on a bass body. I will give it a few more weeks to harden before I make up my mind.

Mike,

I have tested KTM9 on some scrap mahogany and I am very happy with

the results so far, my only concern has to do with its hardness. I

applied my coats about 8 days ago, I have leveled and buffed it to a

high gloss. At this point I can still put a dent in it with my

fingernail, how long should it take to fully harden, or least cure

enough to not be damaged by a fingernail?

Thanks for your time and effort...

Ryan

<mailto:ryan7rice@msn.com>ryan7rice@msn.com

That's the downside to all waterbornes, they don't get really hard.

KTM-9 will harden somewhat more over the next year or so, but it's

never going to be as hard as catalyzed solvent finishes like are on

most factory solid bodies. That's the main reason I've switched to

polyester, but I had to spend $2000 on a spray booth to do it.

================

[mledbetter]

wow.. that is good to know. thanks for posting your findings..

[Maiden69]

How thick did you lay it? I had the same problem with duplicolor and I know it was because it was shot too thick too soon, one problem you will not get with poly. If you did lay it thick, can you try on another scrap piece, this time sparying it dusted on a few passes for a coat, and only 2 coats a day spreaded evenly. This might help the cure time. and while it will take you a longer time to shot, it will be cured faster. Also, next time you need to wait until it is cured to do the sanding and polishing, when you buff the paint, you accelerate the curing process of that very thin top part of the paint, this will "seal" it, and the "vapors" (in parentesis because waterbased paint don't relese vapors the same way as laquer) get locked in and take longer to dry out.

[bassman]

Maiden,

I brushed it on very thinly, the last few coats were a bit thicker though. This stuff dries to the touch and can be sanded in one hour. The tuts indicated that it could be buffed very shortly after being finished- the only advantage to waiting was that it would shrink a bit less- or rather that shrinking would not be as visible. It is highly recommended that all coats are put on in the shortest possible time period to ensure that the layers all link together.

[Doc]

Here's my 2 cents worth. I haven't used this particular product but I have shot a lot of water based "lacquers" over the lst twenty years or so.

They all seem to take about thirty days to fully cure. The curing is more temperature related than anything else. Thinner coats will help some but a warmer environment will help more.

I do know that you're dead right about timong on re-coat and intercoat adhesion and curing time. The closer the better.

The cost of this stuff really makes me wonder. I read it as aboaut 75.00 a gallon plus shipping? Makes me wonder with the increased dry time why you would use it other than to cut down on your exposure to xylene and toluene, which is a good reason in itself. (I've been exposed to so much of that stuff that it's almost like and essentail part of my diet) I know that all of these are high solids and build faster, but I really wonder about the cost differential.

I also worry about repairability. I just touched up the dents, dings and scratches on a twenty five year old refinish of an old Gibson Hummingbird.. Used Deft back then and I was able with little effort to return it to a very respectable appearance. Can't do that with a cross linking product of any kind.

Am i being a pain with these questions?

[bassman]

Doc,

Repairability issues down the road are a bit of an issue, I have read that it can be repaired-just not as easily as nitro. The main reason I was hoping this would work well is my desire to stay away from the nasty toxins. I have a good respirator, but I would rather stay away from poison when possible.

A question for you- Would a poly/oil finish (specifically, Sam Maloof's finish) have any problems being applied over CA saturated wood? OR can it be used over wood that has been pore filled with epoxy?I am testing this right now, but my test may not reveal possible long term problems for quite some time. I know that the CA will prevent the poly/oil from penetrating as well but I am hoping it could still work.

I also live in Richmond, so I am curious- do work on your own or do you work in a cabinet shop around here?

[Doc]

Ryan,

Most of the time oil finishes, including oil poly hybrids, have to have unsealed wood to penetrate and work properly. CA or epoxies are going to keep them out of the wood structure and you're not going to get the Sam Maloof James Krenov Tage Frid look. The sealed parts will be glassy and chip off easily.

I ran a full time cabinet shop dowm in the Bottom for twenty some years, burned out, went back to graduate school and got a very strange regular job working for the Dept of Corrections.. I still have a shop and lately I've had so many commisions coming at me that I'm back in there 30 or 40 hours a week and I'm booked for the next year or so.. I only build furniture now and won't touch commercial work for anything. I'm over in Northside off of Staples Mill.

[mledbetter]

I'm interested in KTM9 for the same reasons.. Nitro and so many of the solvent based sprays are horrible for personal health and not to mention the environment.. now i'm not what i would consider an "environmentalist" by any stretch.. i dont' even recycle.. but it seems like the responsible thing to do, if an alternative exists, to seek it out.

That being said, i was dead set on oil finishes and gave TruOil a pretty serious run. You might want to try it. It won't work over grain filler for the reasons described above, BUT you can use IT as your grain filler.

Basically, rub the wood down with the oil and then rub it in with 320 sandpaper and the oil and sawdust will settle in and level out your grain. Downside is you can't aply a stain after that. You can however tint truoil with TransTint or something like that, so the answer might be to use the oil/sanding method first then a tinted oil for several coats, then regular oil for a few more coats.

TruOil has a heavy poly content i believe. I put about 10 coats on a test piece of ash that I had dyed green and it's incredible looking.. but I rushed the coats.. sometimes putting it on only waiting 30 mins since the last one! i'm impatient that way with something new. however, 10 coats and I had a mirror smooth finish, deep glass like shine, would have never thought it was oil. It never passed the fingernail test though. A buddy of mine that does gun stocks though said he doesn't have that trouble with TruOil.. and to survive out in the field it has to be durable, so that's why I think i just rushed it.

EB uses truoil on their guitar and bass necks.. i think they just do a dip and a wipe though, as if you've ever seen a used EB instrument the necks are usually black with grime and are completely unprotected.. moisture sealed, but no protection from dirt or other oils. I haven't completely given up on truoil, i may try it one more time and must make sure i wait 1 to 2 hrs between each coat.

Check out www.framus.com and look at their diablo guitar.. it's a tinted oil finish. I don't even think they grainfilled and it's gorgeous.

Last thing.. it seems to me if you're worried about poly choking out vibrations and tone qualities, then you should really be worried about grain filler. Switching to nitro doesn't automatically give you a more resonant instrument as there is still an equal load of grain filler down there clogging up all the pores. So it seems logical to me that if people want the most resonant tone possible, a dye and oil treatment is the way to go. Low to Med luster tung oil, or 4-5 coats of truoil.

[mledbetter]

Any more news on the KTM-9?

[bassman]

It still looks good, but it still is not hard enough. It is getting harder and harder everday- it is approaching an acceptable hardness but it is still no there- I just really hope it makes it to that level of hardness neaded for an instrument.

[Doc]

Ryan,

How long has it been since you finished putting the stuff on? How warm is the room that you are keeping it in?

[mledbetter]

I've read both Doolin's and Greven's tutorials.. Greven says wait 1 hour between coats. Other things say you can go 30 mins between coats.

I'm wondering if the hardness issue is 1) too many coats too soon and 2) wasn't fully cured when buffed which if I understand correctly, can trap moisture underneath the shell.

Option 3.. KTM-9 looks gorgeous but LMII is glossing (no pun intended) over the fact that it's not a very hard finish. It sounds too good to be true, and may in fact be just that. I'm anxious to hear though. I may bite the bullet and buy some myself too, and maybe spread the application out over 3-4 days and let it cure longer before the final buffing. Making sure the room it's curing in is warm and bone dry can't hurt either.

[bassman]

Doc,

The room temperature is between 70 and 75, warm enough. I keep my house pretty warm in the winter. I have forced air heat, so the moisture is no problem this time of year, on the contrary keeping any moisture in the air is very hard to do right now.

Are there any possible job openings in your shop at this time? I am considering going back to building full time in C'ville, but the lack of benefits and drive time were killing me. My current job is just not fullfilling enough, and my boss is just plain negative all of the time.

Mledbetter,

I am pretty confident that I applied the finish in the appropriate manner.(besides a bit of sand through in a few small places, mainly the edge, of the intial epoxy grain filling coat) However, that is not to say that a different approach wouldn't help with the hardness issue. On the little KTM9 forum a couple of users complained about it's "softness"- I was hoping they were just doing something wrong. I have not given up on it yet...

[Doc]

Ryan,

It sounds like you just need to be patient. I have been real interested in this stuff 'cause I am tired of fumes, and it would be nice to be able to do the finishing in my basement shop instead of the main shop with its clouds of sawdust and solid surfaces chips to creep into the final product and drive me crazy.

I haven't seen an acrylic yet that hardened up in a reasonable time frame. Tis doesn't, unfortunately, appear to be any different. If it was cheaper I might but some and fool around with it, but at seventy five a gallon I'll wait.

[Doc]

Ryan,

It sounds like you just need to be patient. I have been real interested in this stuff 'cause I am tired of fumes, and it would be nice to be able to do the finishing in my basement shop instead of the main shop with its clouds of sawdust and solid surfaces chips to creep into the final product and drive me crazy.

I haven't seen an acrylic yet that hardened up in a reasonable time frame. Tis doesn't, unfortunately, appear to be any different. If it was cheaper I might but some and fool around with it, but at seventy five a gallon I'll wait.

[mledbetter]

With permission by John Greven, i'm posting his reply to my email asking him if 1) he found KTM-9 to get to a satisfactory hardness and 2) does he still use KTM-9 or has he switched to something else as it appears Mike Doolin has.

Marcus

it does take time to fully harden and when done, it is comparable to lacquer, which is to day it is not has hard as a polyester finishe (like Taylor), but certainly hard enough to be long term serviceable. I cook the finish between coats using heat lamps (2 250 watt lamps about 3.5 feet above the work area). This accelerates the cure and makes the finish hard enough to buff out in a day. Other than that, I use the same process as Mike and yes, I am still using the KTM=9 until something better comes along.

John