Suggestions On Pore/grain Filling

[Doc]

First comment to "Westhemann" Nice snide put down earlier. It seems that a lot of you guys on this post have a manners problem.

I have a very large box full of the "get with the times" garbage that salesmen have assured me would replace the fuddy duddy stuff I was using. This includes about five different generations of waterborn finish and epoxy whatevers.

I've used epoxy filler. I have no trouble with new stuff but only if it does a better job, whatever that means to you. I've found it to be tempermental and much more problematic than "old guy" style semi-paste. I don't read all of the posts here, but there seem to be a lot concerning difficulties with catalysed products in general. This has to do with how the stuff works chenically.

I was commenting on the use of two part epoxy glue as a filler. It's glue, not filler.

Stewart Mac sells an epoxy filler that I've tried and I found it to be overly sensitive to temperature and humidity. It was also a beast to sand after it cured overnight.

I've always hated semi-paste but find it easier to deal with and more predicatble. Especially so for a beginner.

There are a lot of terms that get thrown around here and if you haven't read a whole lot of threads can confuse you. Poly is not just poly.

The Minwax type of one part polyurethane is a far cry from the two part automotive paint that a lot of guys here use. The latter is a professional only, highly toxic specialty product that shouldn't be messed with without a full filtered spray booth and a lot of instruction, not just grab it and go experience. The former is a floor finsih that will work in a pinch

Minwax polyurethane has two drawbacks, It has a long dry time, even the quick dry, so dust and bugs like to find their way into it. It also has intercoat adhesion problems. The coats bond mechanically. You have to sand it with a coarse enough grit to leave microscopic scratches for the next coat to "grab" to.

If you're worried about the yellowing of nitrocellulose lacquer you'll really hate polyurethane. It starts out a lot yellower and gets worse. Us senior citizens have an advantage in that I can look at stuff I did twenty five years ago and see what has happened. I hate everything I ever finished with conventional polyurethane.

Polyurethane's big avantage over nitrocellulose is scratch resistance. This is important for floors, less important for guitars and furniture. They will both dent. because you're not denting the finish, usually, you're denting the wood underneath and the finish flexes and follows the dent.

Get a copy of Bob Flexner's book on understanding wood finishing. It comes close to being gospel, is easy to read and available in paperback at a lot of Home Depot's and Lowe's in the do-it-yourself section.

[subject17]

i see,

well i am headed back to the de-pot tommorow morning to get some supplies.

i will for sure be heading there to get some things.

i know about the longer drying time.

i have alot of things to learn... and i wish i had the experience needed to shoot the 2 pack poly. (and the equipment for that matter) this is a HUGE undertaking for me. and i know its kind of like drak said to me. the next one is always better.

im doing the best i can to get a good finish this time around and the next time. i can learn from what did not go so right and make sure i do it properly that time around.

as far as finishing liquids go,

what makes poly or nitro better than the other? because as far as i can see.

it looks like they both have their drawbacks.

checking and yellowing versus. unforgiving repairs and longer dry time.

i have decided on poly this time in part because i've seen a beautiful red tele that was minwaxed... LOL... and godinSG made a guitar that was finished in it as well and they both came out great looking.

i've also seen some awesome guitars sprayed with deft... and i will be trying nitro next time around. nitro is a little harder for me to get ahold of though. but i wanted to try both and see what rattlecan i like better.

to cope with the dust and bugs issue... the area i am spraying in, when done. should be as dust free as a human can get it with standard cleaning utensils, and im in arizona. so bugs arent as huge of an issue... though i will setup some traps now that you've said something about it. the drying area is a locked closed shed that gets pretty warm but not HOT HOT.... i think its a pretty good area for all of this.

any other advice is appriciated.

and i didnt want a war in this thread. im just trying to soak up whatever information/experiences/mistakes/victories that you all have had with this stuff and try to apply it to what im doing.

i feel that some day i will try waterbased and epoxy finishes too but thats another time another story and another set of equipment for sure

thanks again.

-RS

[westhemann]

First comment to "Westhemann" Nice snide put down earlier. It seems that a lot of you guys on this post have a manners problem.

dude...it was a joke.you used the "old man" thing yourself...i was just playing off of it,making a satiric comment about you claiming to be an old man.i guess it seems as if you can't handle being wrong.all i did was refer you to what you said did not exist

you know...some people actually LIKE to learn about new things.i guess you are not one of them.maybe the eopxy you used is problematic...but i have not found what i use to react badly with anything at all...it is a very neutral base.

Get a copy of Bob Flexner's book on understanding wood finishing. It comes close to being gospel, is easy to read and available in paperback at a lot of Home Depot's and Lowe's in the do-it-yourself section.

funny you reccomend this...i have this book and he is a big fan of using what works for YOU...not just what every one else has been using for years,and not falling prey to the hype of "old style" finishes

I'm a part time picker who spent 25 years as a furniture maker and finisher. The first thing tht I learned is that is no one right way to do any of this stuff just a lot of basic rules to follow.

your very first post on this forum.maybe you could learn from yourself,if listening to others is such an ego killer for you.,

[Mattia]

I've used oil-based fillers a few times, and I do not like 'em. No sirree. I simply don't like soild-colour fillers, don't like how they work, sand, look, nothing. I've yet to try epoxy fill, but it's being used very successfully by a number of smaller shops/builders, particularly in the acoustic guitar world, because it can seal the wood, pop the grain, and not affect the colouration, all in one go. I'm no big fan of staining most woods that require filling m'self, see. Also, you can tint epoxy if you want to, no probs. In 'non glue' land, I'm quite partial to waterbased fillers, such as the Target product StewMac sells. Yes, you do need about 3-4 applications to get a smooth, even fill on rosewood or mahogany, but it sands rather nicely, is perfectly clear, and is a snap to clean up. It doesn't pop the grain well, however, which is why I generally seal with shellac, fill pores, sand back, re-seal with shellac. Works well for me. If I were going to stain, I'd do it after sanding back to wood post-filling (careful sanding required, so as not to open up any new pores), and before re-sealing with shellac.

[erikbojerik]

I think a big factor in using different epoxies as a grain filler is how hard they cure, depending on the type and brand they can cure to a wide range if hardnesses (I've used geological-grade Epi-Cure from Buehler, and it is literally hard as a rock). So, when you go back to sand it flat, the 'softer' epoxies will sand down nicely, the rock-hard ones will be much more resistant and make you end up with a lot of topography on the surface that you don't want.

[Doc]

Wes,

Did you actually read my post or are you too enamoured with your own cuteness to pay attention? Oh that's right. You're from Texas. Should have paid more attention to your tag line.

I do try new stuff all of the time. Some of it works, but most of it doesn't. It especially doesn't work the way that the average salesman tells you it will or especially the way that the website or catatalog describes. Shops that chase the latest and greatest in everything have one thing in common. They usually lose a lot of money and go broke. Innovation is nice but it isn't always the best solution.

There are some advantages to using catalyzed products. I shoot some catalysed finishes for specific cuatmers. I keep a five gallon container of West system on the shelf and use it for all kinds of bizarre stuff. I even have used it tinted as a filler years before anyone packaged it that way. Not my own original idea, I picked it up from other polite cooperative woodworkers. My experience, and it is only my experience, is that there are more problems encountered with them for the average user. You guys maybe don't remember conversion varnish. This was the greatest thing ever. A two coat high build easy to work with wonder finish. Five years after any exposure to UV it turned lemon yellow and shattered, not just cracked. It turns out that the fumes are really injurious long term. Every cabinet shop in town had switched to it. The guys that don't care after the one year warranty expired still use it. The guys who do don't. I don't notice anyone here even mentioning it. Ten years ago it might have been all the rage because it was new and better.

My opinion, and it's only that, is that someone just starting out is going to make more mistakes than an experienced finisher. My experience also is that oil based grain filler is easier to fix. If you have to have a clear filler it's obvious that you will have to either sand and fill with finish or use an epoxy.

Epoxys all have one thing in common. They use a catalyst. This is what accelerates the chemical reaction involved in their hardening and not really needing a cure time. To my knowledge they are all based on some pretty nasty chemicals. Di-benzyl peroxide and cadmium to name a couple. Safety is a concern of mine because I've used a lot of this stuff for a long time and I'm starting to pay for chemical exposure. I know that the solvents in oil base stuff can be nasty but I don't think that they are as nasty as the epoxy family, They just smell less dangerous.

I don't like any of the grain fillers and wish someone would come up with an easy to use alternative to what we have. I am not a chemist. I'm just a woodworker turned psychologist who has to slog tharough the high gloss swamp on occasion.

Now let's all play nice and go build some guitars.

[ryanb]

... and i will be trying nitro next time around. nitro is a little harder for me to get ahold of though. but i wanted to try both and see what rattlecan i like better.

←

If your choice is between rattlecan poly and rattlecan nitro ... I dare say that you will have MUCH better results with the nitro. When you spray out the nitro, the layers melt together and self-level much better than the poly. Hardware-store spray poly often sprays a very textured surface that would be hard to clean up. If you do use the poly, you need to make sure that each coat is COMPLETELY dry before you do the next coat ... full drying takes a long time (though much less in Arizona of course). If you recoat too soon, you may get a finish that stays sticky for a very long time, and may have trouble with the finish lifting.

But that's just a suggestion.

[westhemann]

right at the moment i am sealing and coating my latest guitar with 2 part epoxy which i dyed black...it's working very well.

doc,pffft

[guitar2005]

I did a Korina Jem copy a couple of months ago. I didn't fill the grain, but ended up filling it with multiple layers of nitro. It was mirror smooth when I was done with it.

As the finish continues to cure, you can now see the finish settlilng into the pores, which I like.

Next guitar which will be a solid color, I was going to attempt to fill the grain with regular wood filler (putty). It comes in several shades, is stainable, readily available and durable. Has anyone thought of this? Sound a lot easier than using Epoxy

[Doc]

The reason to use semi-paste instead of regular wood filler is the open time. The acetone based wood filler will work but it will set up so fast that you will have do a boatload of sanding. It's just hard to wipe off the excess in time. The acrylic types of wood filler set up slower but make a hazey mess unless you are using a solid color. If you're lacquering with an opaque color you could probably get away with it.

One of the reasons I don't like some of the epoxy type products is that they are very heat sensitive. Chemical reactions double in speed for every 10 degrees C that you up the material. Last week my shop, tin roof and no windows for 2500 sq/ft, was over 120F and the humidity was over 85%. Lacquer was dry to sandable in under five minutes even thinned down and retarded 20%. I don't want to think how fast epoxy would cure and solvent based wood filler wouldn't even get off of the putty knife.

They obviously sell a ton of the stuff and some guys here swear by it.

Different strokes, whatever works.

[AlGeeEater]

I just used some of the stew mac waterbased grainfiller. 'Been happy with the results so far. It cures pretty fast and cleans up so nice.