finishing a burl

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hughbie

hughbie

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ok, i'm doing my first burl and finding it more difficult to get the shiney finish that i'm used to on regular grained wood.

it's coolabah burl from nolan (thanks again)

is coolabah extremely oily or just hard to finish or......(perish the thought) is it me?
i do CA on all my woods and never had this much trouble. i've actually taken the finish off three times already.

HELP!
 
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Cocobolo IS very oily. Wipe it down with DA before you apply first coat. If that doesnt help get the DA rag real damp and run lathe and wipe it down for a bit to try to soak up some of the oil.

good luck
Dave
 
Also the surface contains many different textures so to speak unlike a straight grained blank so you may be sanding through your CA because of oversanding.
 
dave, it's not cocobolo, i know that a very oily wood, but it's coolabah. another aussie wood i think, ask nolan. is it aussie?
nolan - you might have hit it on the head. since this is my first burl and not straight grain like i'm used to, that just might be it. i'll try some more..

patience is not one of my stronger points

thanks guys
 
In the begining that was my problem.

Originally posted by hughbie
<br />dave, it's not cocobolo, i know that a very oily wood, but it's coolabah. another aussie wood i think, ask nolan. is it aussie?
nolan - you might have hit it on the head. since this is my first burl and not straight grain like i'm used to, that just might be it. i'll try some more..

patience is not one of my stronger points

thanks guys
Click to expand...
 
I've had trouble with heavy burls too. Maybe something to do with the diff densities of wood. The wood in the blank can be dramatically diff from one end to the other. I've had a couple that would shine like glass on one end, then be dull as heck in spots. And the spots were obviously where the grain or wood was diff.
Just a thought.
 
On most of the woods that seem to have trouble taking a CA finish, I use Lacquer Spray or Enduro.....IMHO, if you are having to wipe down a wood with DNA to get rid of the oil before applying the finish, you may be asking for trouble. Not always, but probably often.
 
If you think you need to wipe down the wood to remove excess oil, which I doubt is the case with Coolibah, use CA accelerator. There has been quite a bit of discussion about not using DNA in the last few months.

Also, what is your CA process?
 
i agree with gerry, use the accelerator or acetone to wipe oily woods... but i also reckon nolan is on to something about the different grain patterns, the absorption in certain areas is a lot different so it's harder to get a uniform coat of ca the first time 'round. you might just have to keep taking it down to smooth until you get things sealed up evenly... this has been my experience with red mallee burl.
 
I think I understand wood finishing pretty well, but I am always willing to learn something new.

Notwithstanding the issues surrounding oily wood and getting the finish to "stick", since the shine is in the finish and not the wood, why would the type of wood make a difference in how shiney the finish is?

jeff
 
Makes all the difference in the world--some days some woods can be a real bear to get the finish right. One of the things you can see reading these post----there are many different thoughts on how to get-er-right. There is not a perfect way to finish every wood. Heck if there was we would all be doing it that way.
 
Gary,

Just saying that they are different, doesn't get us to a place of more knowledge. How does it make a difference. Are there certain woods that are always hard to finish (oilyness aside)? What woods are they? Why are they difficult? Keep in mind that we are talking science here, results should be repeatable. If they are not, then it would seem that the problem is not the wood or the finish, but the person applying the finish.

Where am I wrong?

jeff
 
There are no two pieces of wood alike plus there are a lot of variables when applying CA finishes. I don't buy science unless you normalize the variables.
 
Originally posted by louisbry
<br />There are no two pieces of wood alike plus there are a lot of variables when applying CA finishes. I don't buy science unless you normalize the variables.
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OK then Louis, please explain how the different woods effect the shine of a CA finish.

This is science by the way. The formula of CA glue or lacquer is science. The curing process is science. The variables you have mentioned are part of the science as well.

Getting back to my original premise. The shine we seek is not in the wood. If it were, we would not need a finish, other than to protect. The shine is in the finish. This is proven by the fact that after the finish is applied, we minipulate it (not the wood) to achieve the desired sheen that we want. Or we rely on the manufacturer of the finish to do it for us (gloss, semi-gloss, satin, etc).

If I am wrong, show me. If I am not, please explain how a piece of wood effects the shine.

Until that time, if I can't get the shine I want on a piece of wood, I will continue to believe it is my fault, not the wood's fault.

jeff
 
Let me preface that I am not an expert at finishing but have formulated educated opinions based upon reading and experience. Also I have sanded and polished some but not all wood types to achieve that shine we are looking for without applying a finish. However in most instances I applied a finish so that the shine would last. If the finish is propoerly applied and polished it will enhance the shine. I agree with not faulting the wood, but you should respect the woods characteristics and properly prepare the wood prior to applying a finish. You also have to apply that finish in a controlled environment to see the same results every time. Environmental aspects include but are not limited to age and viscosity of the CA, ambient temperature and humidity, speed of lathe while applying the finish, type of application material (some material has better CA acceleration characteristics) and the list goes on and on. It is my personal believe that not only the final finish affects the shine but also the smoothness to which the wood is sanded and polished and the absorption properties of the wood. This absorption characteristic is one of the reasons why properly sealing the wood prior to applying a finish is so important. Another reason would be grainy wood. Call it science if you want to. I prefer to call it skill.
 
Originally posted by jeffj13
OK then Louis, please explain how the different woods effect the shine of a CA finish.
Click to expand...

Do you want to discuss the characteristics of finishing wood or argue the semantics of "science"? If it's the former, I offer you the following evidence that there is no single effort which will produce the exact results time after time.

Using maple as an example, some maples will gow in the pristine conditions of some of the lesser populated parts of Canada. The water will be fresh run off from snow that did not fall through pollution. The tree will grow in a relatively pollution free environment and in fine loamy soil. Other maples will grow in my mother's yard just outside Washington, DC. The will be fed through rain that falls through the high pollution of one of the businest intersections in the country. They will grow in a high acid content clay. They will mature in heavy air pollution.

The impact of the different conditions will make a difference in how a finish reacts which will, in turn, cause the shine to vary. Beyond the example here, changes which occur all over the world, different woods also have different pH's which will impact the results of finishes differently. Different woods have different cell and grain structure which will trap or reflect light differently. Sealing and filling properties of each finish will change the shine of the finish. Shellac breathes better than CA, so a wood that releases some of its water content will find that vapor clouding the shine of a CA finish while the shellac will allow the vapor to be released.

While you "understand wood finishing pretty well", these are experience-based observations over a period of several years while I have finished at least 100 species of wood. For a more in-depth discussion on the aspects of finishing, read our own Russ Fairfield's articles or anything by Michael Dresdner. For my nickel, they are the gurus.
 
Jeff
I read some where that there is an art to every science and a science to every art. The two are not mutually exclusive. There are too many variables in wood for anything to be perfectly repeatable. Sure we can good a good finish on most blanks using essentially the same method but the method has to be adjusted for external and internal variables. We possibly do it subconsciously most times. We may add extra coat or use medium not thick on a particular day “just becauseâ€. I’ve only got a couple hundred pens experience not the thousands of some the members, but it tells me that without the art and “feel†for the piece of wood that I’m working at any particular time, the mechanics of crafting a pen would produce a poor finished product. Bics are produced by science. Take a look through the members photos and you’ll find art.
 
Many of you have misunderstood my posts. I am not suggesting that art (or skill) and science are mutually exclusive. They are not. I I would submit that skill is the proper application of science, and art is the creative application of skill.

Phil, I agree with you that there are many variables, I see these variables as humidity, age of CA,temperature, many of the ones that Louis spoke about in his post. However, I remain unconvinced that the wood itself is a variable as it relates to shine.

Lou, you get it. I'm not yet persuaded, but yoru arguments are compelling. I am interested in learning more in the interest of becoming a better finisher. I would be interested in knowing how and why the examples you gave impact the shine of a finish. For example, how does PH react with a finish? which finishes? If I can learn that, I can avoid or control that problem. I agree with your example of CA and shellac, but, again, that is about the finish, not the wood.

I agree with your comments regarding Russ and Michael. I would add Jeff Jewitt to that list as well.

Thank you all for the discussion.

jeff
 
jeff, scientifically the shine is only light bouncing of the surface, whether the surface is wood or some finish is irrelevant.

The smoother the surface, the higher the gloss. When the wood absorbs more of the finish in some places than others, then the surface will have different appearances. the portion that absorbed the finish will have a rougher surface while the portions that didn't absorb the finish will have a smoother surface. thus the same finish applied at the same time and in the same way could lead to two distinctly differing appearances.

the smoother the wood is when the finish is applied can effect this also. If you apply a stain to wood that you sand to 100 grit, it will absorb alot of stain and thus take more of the stain color. If you sand that same wood to 400 grit, it will absorb less stain (the pores are tighter) and will take less of the color.

The same happens with your finish coat. take a piece of Oak and try to get a glass-like finish on it. You will either have to put on many layers of finish or sand and fill the pores before applying the finish. You can use fewer coats with the second method.

So in this case, the portions that absorb the CA will appear dull until they absorb enough that the Ca starts sitting on the surface as in the other areas.

edit: forgot one thing. Other things can efect the clarity of the finish. so, you may have great shine, but the wood will look foggy.
 
Well I have to agree with Jeff. The wood does not effect the shine. I use only thin CA for my finish and I get the same shine every time. I apply, wet sand, and buff. Just my two cents.
 
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