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RETIRED
12th November 1999, 11:26 PM
An email that I recieved today:

Hi ,

Saw your response on a woodworking forum and figured you must be an
Aussie, so thought I might ask you a question which the yanks cannot
answer. I am building a 50mm thick table with cured Redgum and filling
the knots with a black epoxy to give a high contrast finish.

I was thinking of using an epoxy on the table top as well, but have
lately been a bit dissuaded by claims it "isolates" the timber from
touch . Any brilliant ideas for finishing Redgum? Is Danish oil a
viable option to produce a high gloss finish?

Thanks in advance, sorry for the interruptus!
Name and address removed to protect the innocent. http://ubb.ubeaut.com.au/ubb/smile.gif

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Ian () Robertson
"We do good turns every day"






[This message has been edited by (edited 12 November 1999).]

Shane Watson
22nd November 1999, 11:46 AM
Finally I get around to replying to something! Stupid putors http://ubb.ubeaut.com.au/ubb/smile.gif

Theres a heap of different finishes available for you to use. I wouldn't suggest epoxy, but it is an option.
It really depends on how you can apply a finish, I mean if you havn't got access to spraying facilities then some good finishes are out of the question or are going to be harder to use.

I would use a lacquer, an acid cat. lacquer. this can be rubbed back to match most finishes and to any gloss level. It is also resistant to 90% household chems. Would apply it using spray so as to obtain an even surface. Although it can be applied by brush or rag( rubber ).

As I said above there are many different options, this is just one that I would use, others will have different opinons. Hopefully they will fill you in on there's and you can go from there!

Cheers
Shane!!

Marcus
22nd November 1999, 06:13 PM
Hi Shane,

Thanks for the tip, seems that an oil/wax combination produces a pretty good looking result but the durability is questionable so perhaps the lacquer approach is better. Can you suggest a brand/precise type? I can get access to a spray gun...

Marcus

S Hayward
22nd November 1999, 08:52 PM
Don't forget.
When applying a finish to a top it is most important to cover both sides equally. Three coats of laquer on the top and a so called "sealer" coat on the bottom
will create an imbalance in the way the wood breathes. Usually this results in some mild to serious cupping. We supply kitchen bench tops and this is the most common problem encountered.
Regards
Shaun

Shane Watson
23rd November 1999, 11:16 AM
Marcus.

There are more brands than there methods! Again everyone will have there own likes and dislikes.
I use Mirotone 830/30. But if you want gloss then you would just use 830. This is my preference which works great in my climate. I might suggest you phone round some of your local furniture manufacture's and ask what they use, this will give a better idea of whats better to use for your local climate etc.
As Shaun said, it is important to get a good even coat on the underside of the top! I too have seen and repaired many tops and counters etc that have had little or no ( ! ) coating on the underside. I myself don't match the amount of coats both sides ( eg, three coats on top & Three coats on underside ) But I do ensure a good even coverage and I have never had a problem.

As for wax finishes, these can be great and if done properly will have little difference to the look of a lacquered finish ( although there are huge arguments about this, but note, I said done properly http://ubb.ubeaut.com.au/ubb/smile.gif ) But for table tops there is a huge advantage going for lacquers, even polyurethane. But thats another story http://ubb.ubeaut.com.au/ubb/smile.gif
HTH!!
Cheers
Shane...

Mac Simmons
25th November 1999, 09:10 AM
Hey Mates, http://ubb.ubeaut.com.au/ubb/smile.gif

Our climate, is much different then it is down under.

You do not find furniture "coated" on both sides in the USA.

Most coatings including waxes, except for some of the super catalyzed coatings are pourous enough to allow the moisture to both enter and also leave the coatings. this transfer also would apply to the uncoated woods.

How important it is to "coat both sides of the wood" (timber) maybe more important in certain climatic conditions? In some other cases it just maybe a waste of time, and your material.

(It may look, and sound better when selling the job, then it will do in preventing warpage, or expansion and contractions in the woods)

G'day http://ubb.ubeaut.com.au/ubb/smile.gif

Mac


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Shane Watson
25th November 1999, 11:23 AM
Hi Mac!

Coating both sides ot the top is important. but your right, it has a lot to do with climatic conditions. And also personal preference. I know a lot of local people that don't seal both sides, but I know as many if not more that insist that its done.
I really don't know the scienctific answer but I am sure there is one out there http://ubb.ubeaut.com.au/ubb/smile.gif
Personally, I do coat both sides, but I don't put equal amounts, I don't believe that is neccessary.
But as I restore a lot of antiques I can also say that most pieces I restore that have tops and large ones at that are not coated both sides and are still as flat as they were when they were made!
I really think it comes down to the type of finish you use. Catalized lacquer's and polyurthane etc don't really allow the timber to breath so if both sides aren't coated then the uncoated side will do all the breathing.... Eventually having to give way hence the cupping, shrinking, expanding etc that can happen....
Whadya think??

Cheers

Shane!!

ubeaut
25th November 1999, 01:25 PM
Hi Guys

Good discussion. In my experience to leave one side of redgum uncoated would be to almost invite disaster by means of warping and bowing etc. I reckon red gum would have to move around more than almost any other timber even if it has been dried for 100 years.

I have also found that different timbers will react differently in the Oz conditions. English and American Oak antiques can literally explode when brought into our summers. Cedar antiques are very rarely coated both sides and seem to stand up to the conditions quite well etc. etc. etc.

One little note to those not in the know. Never coat the inside of a bookcase. Leave the timber raw. This will stop mildew etc. on the books.

Thats my little bit.

Cheers
Neil http://ubb.ubeaut.com.au/ubb/smile.gif

Mac Simmons
27th November 1999, 01:51 AM
Hi Shane, http://ubb.ubeaut.com.au/ubb/smile.gif

In different parts of the countries there is completely different temperatures, and moisture conditions.
As I mentioned most coatings are pourous enough to allow the air exchange to come and go ( as all coatings are not equal in this characteristic, the transfer will be greater with some coatings then in others) Polyurethane coatings is also pourous as they will also allow silicones to enter the pores, where the two component catalyzed coatings will not allow penetration.

The only time I ever coated both sides of the woods was when I replaced a section or part of the furniture because it had warped.

I say, do what ever you feel will work best for your work in the long run.

G"DAY

Mac http://ubb.ubeaut.com.au/ubb/smile.gif


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knuckles
27th November 1999, 10:03 AM
Mac

You obviously have not ever used Redgum. It would not be wise to leave the under side uncoated. As Mr Neil says, "It would be inviting disaster." I will bet that there are many people out there who can substantiate this fact.

You are right about the finishes being able to let the moisture in and out. However, if one side is not coated it will suck in the moisture dramatically whilst the coated surface will let it in very slowly, (almost not at all) thus creating a cupped piece of timber due to the expansion of the uncoated and now moist side of the timber.

A simple experiment with moisture will prove this to you. Coating all surfaces with an even number of coats will allow moisture to penetrate at a more even rate all over and should control the amount of warping etc. This is plain old common sense, not scientific fact.

Knuckles



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Don't mess with me! I know where yez live and I might just pay yez a visit. Capish?

Mac Simmons
27th November 1999, 02:53 PM
Capish,
Don't come alone....

If it take the same amount of coats on both sides to keep it from warping, so be it.

As there are many different coatings that could be used that would allow the moisture in and out evenly.

Why not just use a coating that the moisture will not penetrate.

Now, that is common sense.




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S Hayward
27th November 1999, 04:56 PM
But wait, there's more.
Len Fischer from the Woodcraft Guild of the ACT published an article on finishes and their ability to provide a moisture barrier. It was interesting to see the differences between various types. It was, as I recall, an extract from some other mag but I believe the info to be based on sound technical fact. If I can dredge up a copy I will post it.
Sorry Mac, but the only type of coating that wont let any moisture in is a two inch layer of epoxy. Those who specialise in this kind of bastardisation of fine or not so fine woodwork ought to consider another occupation/hobby. Purely an opinion here of course. Why not appreciate the medium with which we choose to work and let it be. In other words, if it wants to move, as it will, then let it go. Just make sure the design allows for this. As for it not being necessary to coat timber both sides in some parts of the world but essential in others, I don't entirely agree here. Firstly, in a mobile society you never know where your work will end up. The conditions will change. Also, where in the world does humidity stay absolutly constant? I agree that some areas experience greater variations than others but almost everywhere experiences some variation from week to week or month to month. If you are going to offer guarrantees on your work you need to account for as many variables as you can. I believe in covering your rear as much as you can in this litigious age in which we live. I also hate having to go back and fix problems. Best to avoid them in the first place.
Wow, isn't woodworking an interesting game?
Cheers
Shaun

Shane Watson
27th November 1999, 08:32 PM
Mmmm. Macs right, do what you feel works best! Like I have said before, I know of people locally who don't coat both sides. Do they experince more problems than I do?? Who can really tell.
But if a client came to me and asked my advise I would advise a coat both sides.
Theres also evidence that the secureing system of the top to the base can cause problems. Timber moves! It a simple fact, as timber is alive even in death!
I still don't believe that equal coats both sides are required, look at it this way - Is a professional going to spend the time neccessary in coating, sanding, coating, sanding, coating both sides equally? Not unless they can afford to loose profit! I can't! Unless you coat and sand the top and underside equally, there will be very different amounts of coating between the two sides. And I don't think I have seen an underside of table finished like the top yet. No matter how high the standards of workmanship.
How us aussie's do our work will always more than likely be different to the rest of the world. Thats what makes us Aussies http://ubb.ubeaut.com.au/ubb/smile.gif But its not neccessarially better than anywhere else.
It really does come down to your own methods. We can all advise, but in the end its always our own choice, and our mistakes will always teach us more http://ubb.ubeaut.com.au/ubb/smile.gif

Cheers

Shane....

RETIRED
27th November 1999, 09:26 PM
Well, Marcus you really started a great debate with your email to me. http://ubb.ubeaut.com.au/ubb/smile.gif

I finish both sides equally with the finish I use (mainly N/C lacquer) and yes, Shane even table tops, just fished some chairs and the seats, which are detachable were lacquered equally top and bottom with 3 coats.



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Ian () Robertson
"We do good turns every day"

S Hayward
27th November 1999, 10:14 PM
Can't quite let this one go yet! Ever slipped a hand under the dining table between mains and sweets, when the conversation has turned to something less captivating than table finishes, and discovered the underside feels like a bit of 40 grit? This is an incredibly disappointing moment when you have been quietly congratulating the maker for a job well done on table then the very object of your praise rips half the skin off your fingers. If you don't intend to polish the bottom, or are only going to give it a rough coat, please cheat a bit and polish well at least 250mm in from the edge. ( 10 inches for our US friends )This way the dinner guests can only complain about the food.
Bon appetite
Shaun.

RETIRED
28th November 1999, 07:19 AM
The reason that I finish the underside of table tops is that some people I know spend a little time "under the table" http://ubb.ubeaut.com.au/ubb/wink.gif and I wouldn't like them to think that I had done a lousy job.

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Ian () Robertson
"We do good turns every day"

knuckles
28th November 1999, 08:11 AM
Last time I felt the bottom of a table during a dinner party I found a lump of fresh chewing gum. What a sticky situation. I was feeling for something else. Not a pleasant discovery.

I used the equal coats scenario before as an example. I believe that you should at least give one good coat on the bottom and not just sanding sealer, it must be the finish itself. This will still retard the amount of moisture absorbed.

If you happen to be one of the idiots who just uses sanding sealer as a finish (and there are plenty of them out there) then learn the correct way to finish. But I digress.

As Mr Hayward says "please cheat a bit and polish well at least 250mm in from the edge."
If things are so tight for time on the furniture manufacturing front that you can't afford to take an extra 10-15 minutes to finish the underside of a table then maybe it is time to look for another occupation.

Pride in your work alone should dictate that the bottom receives something better than just a quick squirt from the gun. Especially if you are producing high class one off furniture.

If you are producing pine junk for the bottom end of the market then you may get away with the less professional approach.

There is much, much more to be said on this important subject but I have had my say for now.

Knuckles

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I will can come alone. (Where ever and when ever I please.)

Mac Simmons
28th November 1999, 08:33 AM
Shaun Hayward,

I think you are either exaggerating, or you should reread that article about 2" of Epoxy is the only way to prevent moisture from entering into the woods. No finish is 2" thick, and the cost of a finish like that would be to expensive for customers.
There are other finishes that would seal out the moisture like Polyester, and a catalyzed Polyurethane.


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S Hayward
28th November 1999, 09:38 AM
Yes Mac, I did exaggerate. It's the way here in Oz. Keep on checking out this and other Australian BB's and you'll come to understand the way we take the .
Have nice day.
Shaun.
Ps Mac, call me Shaun, no need for formality here.

Shane Watson
28th November 1999, 08:48 PM
knuckles, Mate if you can prepare and polish a table top in 10-15 minutes, your a genius http://ubb.ubeaut.com.au/ubb/smile.gifGeez I spend that alone in preparing it for finishing, and thats my quick method for that bottom end pine junk http://ubb.ubeaut.com.au/ubb/smile.gif Don't like keeping time when I do first class pieces http://ubb.ubeaut.com.au/ubb/smile.gifUnfortuanatly this time frame only allows for a quick squirt of a gun, as you put it. Also, I do fully polish all tops on the underside at least 300mm in from the edge, This really dosn't come into the discussion of fully coating the underside. Chairs, I do fully coat the undersides, if they are a timber seat of course http://ubb.ubeaut.com.au/ubb/smile.gif But since we are talking about tops I havn't bothered to mention that yet.
This is a good discussion and shows good example of different techniques used all the over the world, lets not turn it into a slinging match. We all should be willing to listen and learn as well as teach. Theres always more than one way to complete a task, one way may be better, but other ways may be more practicle, each job will determine that! All professionals will swear there way is the best, but then we've more than likely been doing it that one way most our lifes http://ubb.ubeaut.com.au/ubb/smile.gif
Cheers

Shane.....

S Hayward
28th November 1999, 09:29 PM
Hi Shane
You raised some good points and I for one have found this whole discussion not only good fun but also informative. If you read back through the previous posts I'm sure you will agree. I can also sympathise with Knuckles who seems to have a low tollerance for "pine junk". I guess everyone has to start somewhere and in woodwork it seems to be rough and ready items in Radiata. Rough from start to "finish". The trick is, to learn as you go, look at the work of others and learn from it and most of all keep an open mind. We all get firm ideas about some things but if we don't look aropund once in a while we will be making cheap pine stuff forever. I hope this discussion has prompted others to have a think about their methods and review what they do.
I know I've picked up a few tips.
Happy polishing.
Shaun.
Ps. Are you any the wiser Marcus or just more confused?!!

RETIRED
28th November 1999, 11:36 PM
Well,Well.

I do a lot of "pine junk" because that is what my customers WANT, BUT, pine is a timber and every thing in pine is constructed and finished the same as it is for the high end. I have also made furniture from ply, mdf, packing crate material, masonite, steel and any other man made or natural product.

I'll bet that when oak or walnut was readily available some one probably said to Chesterfield or some of the other great furniture builders that we try to emulate, "why are you using that cheap,ordinary crap for?"

REMEMBER THIS: beauty is in the eye of the beholder and the beholder is generally paying the bills by purchasing something from you.It does not mean that you have to compromise your workmanship even though you may be prostituting your "artistic beliefs."

I know so many so called artists who can indulge their artistic fantasies because they are are in well paid jobs and if they had to rely solely on what they produced would be being paid for by you and I via the dole.



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Ian () Robertson
"We do good turns every day"

S Hayward
30th November 1999, 09:00 PM
I'm signing off on this topic after this post as it has digressed a little. I have to reply to though re Pine.
, it's a fact that Pine is the entry level timber for woodworkers. It's cheap, readily available and comes dressed. This means a fair amount of very ordinary stuff is produced using it. I don't have a problem with Pine as a timber but because of all the poor quality work around using it I believe most things made in Pine, good or bad, are not valued as highly as equivalent pieces in some other species. Not a fair situation but lifes like that. Sure the customer foots the bill and I've used Pine on occasions like everyone else but I certainly don't look for work in this species as it is hard to get the right returns on your efforts. I didn't mean to offend anyone with my previous "pine junk" comment but it is a sad fact that most of the work offered for sale in Radiata falls into this category. The abundance of shops devoted to retailing this stuff are testimony to the fact there is a legitimate market for pine furniture but as woodworkers we should always aim to improve our skills, reputations etc, and progressing to more "credible" timbers is a good move.

Keep up those "Good Turns"
Regards
Shaun

Marcus
1st December 1999, 04:32 PM
Hi All,

Well, My latest thinking on this delightful subject is to maybe use something like the Estapol 7008 2 pack clear finish.

Does anyone have specific experience with this product?

Marcus