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Discussion Starter #1
I am working on something and wondering what to finish it with as I want a stand out piece. I had in mind an Oil based clear polyurethane as it will enhance the timber grain, stain and scratch resistant.

I have attached pics of the timber piece in its raw state and a close up of the timber with more work done. I still have a bit to do and need to sand it down to get it as silky as possible. Will show the final product when done

Joos
 

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The only problem you might experience finishing the wood with an oil based polyurethane is it will yellow as it ages. If this is an issue you could coat the wood with linseed oil to bring out the grain. Then seal it with one coat of Zinsser Sealcoat and topcoat it with a water based polyurethane. The water based polyurethane would remain clear.
 

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Discussion Starter #3
Hi Steve

Thanks for the previous information. I have made some progress with the Red Gum "wine rack" I'm working on.
I was wondering if it is normal for wood to still crack after 2 years of cutting. I did notice some moisture near the center of the log while drilling the holes mainly around the knots, that distinct drilled wet timber smell.

I also have minor imperfections in the wood (photo's attached), do I leave them or putty it out and smooth it over prior to the final sanding. I'm only on 180 grit at the moment was hoping to get down to 320. The wood is real smooth with the 180.

Being a novice at this I now realize there are so many fields of this project that I have no Idea about. Its not just about having the idea, sourcing the wood, cutting it to length, sand to the point where you have to use steel wool and then varnish or oil the piece. So much more than just that :smile:
 

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Red Gum

This looks to me as Eucalyptus? If it wasn't completely dry when you began, then changes are bound to occur. This wood (especially small trees) are especially susceptible to warp and shrink. If cracks appear, it would be a good idea to fill and sand - but if these "imperfections" were there to begin with, they are not imperfections at all but are character and will add to the beauty of the project. There is no better finish than straight polyurethane even tho it will "amber" as time goes by - but this adds to the beauty and age of the project. It will last for more than your lifetime. NO ONE knows what water based urethane will do over many, many years as it has not been around long enough. Consider what happens to Orange Shellac after 60 years? Completely black and hides the product completely.
 

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Red Gum problems.

When I wrote the previous answer, my time was limited and I thought to add a little more. In America, Red Gum comes from the center of HUGE Sweet (white) Gum trees and in years long gone, the "Red Gum" was sold as "Cassiniian Walnut" - and it was just as beautiful as the real thing. There are no Red Gum trees naturally in America, tho they were imported into N CA in the late 1850's by the RR conglomerates for use as RR ties. The project failed miserably as they were not informed that Eucalyptus is not a "stable" wood until it is many, many years old and it literally "walked off the dump"! A tree less than three feet in diameter will warp and twist unbelievably! A really large one produces very stable wood and is extremely beautiful. I bought some from a place near Cajon, CA (The Parrot Ranch) several years ago and it has yielded some beautiful wood and is very stable. The owner there has a block of eucalyptus approximately ten feet long and maybe twelve feet in DIAMETER - not circumference! I was blown away. I hd no idea they grew to such dimensions.
I do know that most woods (hard) such as you have pictured require about an inch per year to completely dry. That means that if a tree is ten inches thick, it will require five years to dry - because it dries all around the tree at that rate. When I dry sich wood, I do not paint the ends, I cover them with heavy cloth or heavy paper and that will retard splitting. The same goes for small slices of cross-grain wood of any species that i'm familiar with.
 

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More on the Red Gum (Euclayptus to me)

:laughing:
When I wrote the previous answer, my time was limited and I thought to add a little more. In America, Red Gum comes from the center of HUGE Sweet (white) Gum trees and in years long gone, the "Red Gum" was sold as "Cassiniian Walnut" - and it was just as beautiful as the real thing. There are no Red Gum trees naturally in America, tho they were imported into N CA in the late 1850's by the RR conglomerates for use as RR ties. The project failed miserably as they were not informed that Eucalyptus is not a "stable" wood until it is many, many years old and it literally "walked off the dump"! A tree less than three feet in diameter will warp and twist unbelievably! A really large one produces very stable wood and is extremely beautiful. I bought some from a place near Cajon, CA (The Parrot Ranch) several years ago and it has yielded some beautiful wood and is very stable. The owner there has a block of eucalyptus approximately ten feet long and maybe twelve feet in DIAMETER - not circumference! I was blown away. I hd no idea they grew to such dimensions.
I do know that most woods (hard) such as you have pictured require about an inch per year to completely dry. That means that if a tree is ten inches thick, it will require five years to dry - because it dries all around the tree at that rate. When I dry such wood, I do not paint the ends, I cover them with heavy cloth or heavy paper and taped and that will retard splitting. The same goes for small slices of cross-grain wood of any species that i'm familiar with.
 

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>>>> If this is an issue you could coat the wood with linseed oil.

Linseed oil is amber out of the can and continues to become more amber with time. If one wants a non-amber a non-amber top finish, a clear, acrylic waterborne is the finish to use.
 

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Discussion Starter #8
Thanks for the info. I still have a bit of sanding to do. I actually don't mind the yellow stain of poly.

Samsay you surely impressed me with your knowledge and history of the Gum. Yes it is eucalypt specie. It weathers gray with a pink reddish colour in the centre.

If I oil the piece with linseed oil will it stop the cracking as the wood is fed or not , and if so can I apply polyurethane over it?
 

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>>>> If I oil the piece with linseed oil will it stop the cracking as the wood is fed or not , and if so can I apply polyurethane over it?

No, linseed oil will not stop the cracking. Wood cracks because its water vapor changes due to the relative humidity it finds itself in. Oil only penetrates a very small amount and will have little effect on the drying of the tree. A tree will absorb or emit moisture until it reaches it's equilibrium moisture content. A tree never completely dries out until it petrifies.

What do you mean by "feeding the tree"?
 

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Discussion Starter #11 (Edited)
I've sanded the piece twice with 320 grid. My next step is to start the poly coating. I was wondering however if 320 was fine enough and how do I get rid of ALL the dust it seems to be every where. I dust and dust and it just seem to move location. I have very limited knowledge on the finishing of such a project my first project ever actually. So many different opinions out there for the way to achieve an end result. 600 then wet sand 1000 and so on. Do I have wet sand it
 

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You can "sand yourself into oblivion" if you listen to some of these purists to be sure. I almost never go beyond 400 grit and you'll have to have some pretty good eyes to find those scratches!! Even 220 is ok if you stay "with" the grain and make sure you get all the imperfections out (which you can do much more easily with 220). I even make pens on my pen lathe and quit with 400 although, my final "rub" is with a folded piece of a brown paper bag! Excellent and cheap finish.
I've learned that one of the very best ways of applying polyurethane is to thin it with regular paint thinner (not even the more expensive "mineral spirits which is the same thing) at a ratio of 60 to 40 or maybe even 50/50. The 60/40/ has more poly than thinner and i apply this with a very soft white cotton sock (worn out) rolled OUTSIDE IN (because the outside is softer - go figure!). I'll apply a couple of coats of that and sand pretty well with 220, blow dust off and tack with a thinner dampened cloth and then maybe two or three more coats, repeating the sanding process (and creating more dust!!! - part of the job) and sometimes even finish off the top coat with a spray can of Minwax Poly. Just wait more than 24 hours between all these coats.
 

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Discussion Starter #13
Thanks. The poly I have is fairly runny tested it on a coaster I sanded back. The current is like constituency is that of heated syrup. Do you think I should thin it more.
 

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i have alot of firewood due to my wood stove, and basically i recall reading an average sized white oak tree that has been recently fell.... can contain as much as 30 gallons of water making up 40% of its weight. I wonder if there was a low temp Kiln around 100 degrees with circulation that could toast ur peice for about a week or 2 and that would retard some of the cracking? But i love the piece youve made and i think the cracks (as long as they dont become detrimental) make it very intriguing, The slick exterior with rustic cracks lookes great =\ gj

im in the process of building a kiln and am not an expert in any arena just offering something that you might could look into?
 

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When I wrote the previous answer, my time was limited and I thought to add a little more. In America, Red Gum comes from the center of HUGE Sweet (white) Gum trees and in years long gone, the "Red Gum" was sold as "Cassiniian Walnut" - and it was just as beautiful as the real thing. There are no Red Gum trees naturally in America, tho they were imported into N CA in the late 1850's by the RR conglomerates for use as RR ties. The project failed miserably as they were not informed that Eucalyptus is not a "stable" wood until it is many, many years old and it literally "walked off the dump"! A tree less than three feet in diameter will warp and twist unbelievably! A really large one produces very stable wood and is extremely beautiful. I bought some from a place near Cajon, CA (The Parrot Ranch) several years ago and it has yielded some beautiful wood and is very stable. The owner there has a block of eucalyptus approximately ten feet long and maybe twelve feet in DIAMETER - not circumference! I was blown away. I hd no idea they grew to such dimensions.
I do know that most woods (hard) such as you have pictured require about an inch per year to completely dry. That means that if a tree is ten inches thick, it will require five years to dry - because it dries all around the tree at that rate. When I dry sich wood, I do not paint the ends, I cover them with heavy cloth or heavy paper and that will retard splitting. The same goes for small slices of cross-grain wood of any species that i'm familiar with.

Hey mate , any idea where Brisbane, Australia is ?

:laughing:
 

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Discussion Starter #16
Hey guys.
Any suggestions on a filler to use to fill the two cracks in the wood?

Secondly I have two holes through the wood. What can I use for a clear filler for the top hole about one inch thick so the bottle standing in the top rests on it while the bottle in the bottom hole can still slide in and out.
 

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Hey guys.
Any suggestions on a filler to use to fill the two cracks in the wood?

Secondly I have two holes through the wood. What can I use for a clear filler for the top hole about one inch thick so the bottle standing in the top rests on it while the bottle in the bottom hole can still slide in and out.
Joos ,

if the gum is still drying and shrinking , filling the cracks at this time might be a tad premature .
And bogging one up later , that has already been filled tends to be tricky , especially getting the finish to match .
Is it really necessary to do so ?
To my mind , those cracks , and others if they come , would be in keeping with the theme of the sculpture .

With the hole that has a bottle above , and below , would it be possible to resin in a 'biscuit' of gum to take the weight of the top one ?

Jock
 

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Discussion Starter #18
What I had in mind was to fill it with resin like glue or something so it is see through from the top and the hole is still usable for both the standing bottle and the one sliding in. Can one use resin and what should I look for any particular type as I'm sure it will be like anything in wood work, not straight forward.
 

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Joos ,

if the gum is still drying and shrinking , filling the cracks at this time might be a tad premature .
And bogging one up later , that has already been filled tends to be tricky , especially getting the finish to match .
Is it really necessary to do so ?
To my mind , those cracks , and others if they come , would be in keeping with the theme of the sculpture .

With the hole that has a bottle above , and below , would it be possible to resin in a 'biscuit' of gum to take the weight of the top one ?

Jock
+1. :yes: Filling in the cracks could prevent shrinkage in that area if the occasion presented itself, and could cause it to occur elsewhere. I would sand to 220x, and blow off dust with compressed air. Make a mix of 50/50 BLO and mineral spirits, for a wipe on to enhance the grain. When cured, you could apply waterbase polyurethane.






.
 

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Discussion Starter #20 (Edited)
Thanks for all the information. Eager to complete the project. Picking up my padded drum sander on Thursday to complete sanding the holes.
 
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