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i need help applying finishing on to my computer desk which is built out of jarrah & silver ash. this is my major project for HSC. i need your expertise as to how to and what finish i should apply on my project. i think spraying polyurethane onto my job is the best option but i was wondering whether i should apply sealer before hand or not. any reply will be much appreciated.:) :) :)
Hi David,Quote:
Originally Posted by david_ghs
I'm running short of time for a complete answer, but watch out for the jarrah dust contaminating the silver ash when you're sanding. Maybe fill the pores with a sanding sealer first and then sand back to bare wood once the sealer's dried - at least the pores won't hold the dust.
Any remnant jarrah dust tends to bleed in my experience and ruin the look of the silver ash.
When you're spraying polyurethane, make sure that it's in a spray booth and in accordance with the MSDS - the examiners will know from the photos if you're working safely or otherwise - it's one of the things that they look for. The above is especially true if you're working 2-pack polyurethane, which releases far more isocyanates than regular polyurethane on curing.
Should you need to spray the table, use this as some of the: "evidence of industrial processes" part of your folio, but make sure that you've got the teacher's OK first.
Finishing is a large part of the project with respect to quality and you need to do it yourself, the reason I generally refuse student requests to spray finish unless it's absolutely needed (as I've got to sign off that students have completed the work themselves - a bit hard if I didn't see you finishing the thing, especially if the quality of finish and quality of workmanship are vastly different.)
If you've sanded with a ROS properly to 240#, you might be able to avoid sanding sealer - it muddies the grain a little bit but, as you know, has a great benefit in hiding small scratches.
I know it's not a straight answer, but I trust that this will help you somewhat.
Cheers,
eddie
Who has to ask as a consequence; Am I the only one who's had trouble with jarrah contamination of silver ash, and how did you guys get around the problem?
thanks very much eddie for your reply it was very useful, and when you say contemination in silver ash when sanding jarrah, is that because the fine jarrah particle gets caught in the fibres of silver ash??
i was wondering if there is any alternative finish material that is suitable for my desk which will need to withstand heavy wear and tear.
also if anybody knows a good hirable spray booths around sydney area please let me along with the price if possible. thanks very much :)
Hi David,
Siler Ash has fairly large open pores that tend to catch the dust in my experience.
Re: spraying, check the MSDS - it might say well-ventilated area (=outside) or it might specify a booth. I'd suggest that you discuss how best to approach this with your teacher.
Cheers,
eddie
Have you thought of using wipe on poly by miniwax. I've just finishing making a bed, and used it for the first time, and am very pleased with result. It goes on easily (with a lint free cloth), no brush or run marks - dries quickly so minimal chance of dust getting onto your work. Two or three coats with a light sanding (I used 600 W&D) in between coats gives a finish as good as spray on.Quote:
Originally Posted by david_ghs
Costs $30 for a can at Bunnings - so you could always buy a can and test it on a sample.
I'm going to be doing some work shortly using Silver Ash with some inlays of Jarra, so I'd be interested to here how you went with the potential sanding problem.
Malcolm
hi malcom thanks for your informationQuote:
Originally Posted by MF3106
i am definately considering wipe on poly as my option, it sounds like a terrific finishing material. if you can post pictures of your finished bed that will be a great help.
*p.s i will be posting pictures of my project when its nearly finished
thanks
david
Hello David
How did you end up with the computer desk? I am using Silver Ash and want to keep the startling white colour. So far , the finishes I have tested have turned the timber pine yellow.
Did you use the Minwax, how did it turn out?
Regrads
Hereward
Hi David
Have you considered a non toxic oil such as one of the Livos products or similar? If you wanted to spray it it would not be an issue but wipe on and off would probably be more economical. Sand to 150 to 180 grit, vacmum and oil with the clear oil such as Ardvos or Kunos. It will bring out the red of the jarrah and in contrast the lighter colour of the ash. You shouldn't have any issues by using it the vicinity of someone who is chemically sensitive either.
Hi Hereward
If you want to keep the timber lighter you might like to consider useing a penetrating oil with white pigments such as the Kunos in white. Don't sand the timber too fine, depending on your project, 150 that way the pigments get traped in the pores, wipe off the excess. If you want a finer finish, sand with 240 grit lightly prior to applying the second coat and reapply or use the clear. This will keep the light sanded look. Neil Scobie has a beutiful cabnit treated in the white, you may have seen it if you visited one of the working with wood shows. Try on a sample piece to see if it is the look you are after. Good Luck
Hereward, I suggest you sand your project to about 400 grit (removing the dust and raising the grain with water between grits) and then try blond shellac. U-Beaut Polishes - WHITE SHELLACQuote:
Originally Posted by hereward
cut it 50:50 with ethanol and apply 3 or 4 coats with a rubber, then scuff sand with 600 wet/dry
then apply 3 or 4 coats, again using a rubber, and scuff sand with something finer than 600
if you can be sure the desk wont get hot liquids or cups, you could continue until you've build up 10 coats of so and then wax the surface,
if you want a hard surface, I'd still go with the multiple coats of thinned white shelac, to seal the timber before I tested the colour effect of harder finishes
I think David finished his HSC project a very long time ago :D
How true, pays to look at the dates......better late then never maybe is another option.