CA as filler - anything new?

[deadedith]

Just wondering what the state of opinion is on the Forum concerning CA as a filler. I've read the older posts but would like to hear about recent successes/failures and also how to account for the success/failure.
Dave B

[tippie53]

We are finding that the CA dries very hard. and can cause some issues upon finishing. CA can be softened with acetone. To help avoid adhesion problems fog the body with acetone then follow up with a vinyl sealer . This gives a better chance for the materials to weld together .

[Ken Hundley]

Hi All! I have been running a "Guitar Builders" Group on LinkedIn for awhile now. I haven't mentioned anything because I have not wanted to detract from Bill and now John's efforts, and this forum has been by far my favorite anyway. You are all more than welcome to join the group, and I have advertised this forum within my group in hopes of furthering the popularity of this forum. If you are on LinkedIn, please feel free to join the group.

I bring this up because of a thread I had started regarding favorite pore fillers. There are a couple of paint and coating experts that have joined and had some comments, and one in particular had some fairly dire warnings....please read the following:

"Adding to your comments, paste fillers have to high silica content and often contain other fillers like chalk. This gives body but also has a colour giving the muddy look. The muddy tone is related to a too high solid filelr content (like silica or anything else alike).

Guy's as a chemist, please do not use CA glue as a filler. As Fred mentioned the health risk is substancial, even using well ventilated space and a mask. Such masks are designed to withhold dust and limited amount of chemicals (when filled with active coal like Norrit) but there is a limit. CA glue gives of too much fumes, especially on a total guitar surface.

Another myth about water borne and solvent borne is that spraying water borne coatings is healthier than solvent borne coatings. SB coatings may have the solvents but the fact that the resins are smaller, the body breaks them down, also when inhaled (cancer risk...) easier. With water borne lacquers, the spray mist and the content of soapy kind of materials for properties are also dissastrous to the lungs and your health. Here the polymer is already at its maximum size and the body cannot break this down. Lungs will encapsulate and may be a starting spot for cancer. Even when the polymer itself is not carcinogetic (cause cancer). Spray mist is aways carcinogetic, regardless of the material in it..

SB and WB coatings are both unhealthy for spray and should only be done when using the appropriate safety equipment. Don't go cheap on your health, rather bring the guitar to a professional painter and pay the fee than die young on a nasty desease when you cannot fullfill the minimum requirements (or seek an alternative type of finish). "

If you are interested, please see the entire thread here: http://www.linkedin.com/groupItem?view= ... mp_2323633.

John, if you feel my mentioning the LinkedIn Guitar Builders Group is inappropriate, please feel free to edit as you see fit.

[tippie53]

Ken
Please feel free to mention anything that may help , or educate , this forum is for all to learn , share and enjoy. All I ask is that commercial ventures ask for the ok for postings as we have sponsors that do pay to support this effort. Educational , information sharing and useful hints and tools are welcome.
You may mention other links , as long as they are helpful to the building community .

[Freeman]

When I was making my koa guitar I did a little experiment on a piece of scrap koa. I masked it in three pieces, pore filled one with SM paste, one with CA and one with Zpoxy. I then shot a dozen coats of KTM-9 to compare the results. I really need to color sand it, buff and take some pictures but I can summarize my experience.

SM is the easiest to apply and sand out, dulled and darkened the flame of the koa slightly. Required two coats to totally fill the pores.

CA was moderately easy to apply, but kind of a hassle spreading and removing the excess. It seemed pretty neutral as far as its effects on the color. Also required two applications.

Zpoxy was a complete pain to apply, there were large quantities left on the wood that I couldn't squeegie off and required substantial sanding before I could shoot the lacquer. It warmed the color of the koa slighly and totally made the grain "pop". It was by far the most stunning after the KTM-9 was shot. One application was all it took (and was almost too much). I pretty much followed Mike Doolin's instructions at LMI and several discussions at the finishing forum at MIMF.

Summary, I used Zpoxy on the the guitar and will on everything else in the future, particularly wood with lots of flame or character. I'll try to get some pics.

[deadedith]

Hey Freeman - good info. Have you tried grain filling with thinned coats of finish material?
Dave B

[Darryl Young]

Freeman, have you seen Todd Stock's youtube videos on porefilling with Zpoxy? There are 3 videos in the tutorial. Here is a link to the first video in the 3 part series:

http://www.youtube.com/watch?v=YYHxMg7n9cI

Freeman, a few questions about your test. Was the finish you used over the 3 test pieces a water based finish? Seems waterbaser finishes don't "pop the grain" like some other finishes and this is one reason why Zpoxy has gained popularity. It seems to have a nice index of refraction that pops the grain and the amber tint adds a warmth to the finished product. I know of some luthiers that don't want to use the heavy zpoxy on their instrument and choose a sealer that pops the grain for the same affect. This is an alternate way to achieve a nice look with waterbase finishes.

What viscosity and brand CA did you use for the pore fill on your test piece? How did you spread it?

Forgive my ignorance, what is the other product tested you called SM?

[Darryl Young]

John, does it help to tooth the CA before applying a sealer? What brand vinyl sealer did you use over the CA?

[Freeman]

Hey Freeman - good info. Have you tried grain filling with thinned coats of finish material?
Dave B

The finishing materials that I have experimented with have been (in order) StewMac rattle can nitro on the first two, StewMac waterbased lacquer on the next few and KTM-9 waterbased lacquer on the last one. The first ones were all either rosewood or mahogany and were pore filled with StewMac paste filler, followed by several thinned coats of the final finish lacquer to seal it. I then applied a lot of thicker coats to build the finish, typically sanding every three.

Freeman, have you seen Todd Stock's youtube videos on porefilling with Zpoxy? There are 3 videos in the tutorial. Here is a link to the first video in the 3 part series:

http://www.youtube.com/watch?v=YYHxMg7n9cI

Freeman, a few questions about your test. Was the finish you used over the 3 test pieces a water based finish? Seems waterbaser finishes don't "pop the grain" like some other finishes and this is one reason why Zpoxy has gained popularity. It seems to have a nice index of refraction that pops the grain and the amber tint adds a warmth to the finished product. I know of some luthiers that don't want to use the heavy zpoxy on their instrument and choose a sealer that ops the grain for the same affect. This is an alternate way to achieve a nice look with waterbase finishes.

What viscosity and brand CA did you use for the pore fill on your test piece? How did you spread it?

Forgive my ignorance, what is the other product tested you called SM?

I can't view the vid at work, I'll check it out later. Answers

1 - yes, on the koa guitar it was waterbased KTM-9. I asked at MIMF what the best filler for that finish on koa was and several recommended epoxy for exactly the reason you said. Mike Doolin also highly recommends the combination of Zpoxy and KTM-9 (altho he has gone to something else recently)

2 - I used standard old medium viscosity CA that I had on my workbench - nothing special

3 - "SM" meant StewMac, just their standard Color Tone product. I had uses that with acceptable results on all my previous instruments.

I'm up to my ears in alligators right now so I probably won't get the pictures of the test piece posted anytime soon. Here are a couple pictures of the tricone itself however

[tippie53]

No , we found that lacquer thinner worked best to get the sealer to bite. The CA dries so hard that it can have adhesion issues . Fogging with the pure thinner worked , as it softens the CA enough to let the vinyl sealer to weld in.