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Results 1 to 15 of 22
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11th June 2014, 08:00 PM #1
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Can you describe what a clear coat 2K off the spray gun mirror finish is like?
Compared to a high quality varnish brush. Does it have that deep glass look like off the brush or is it almost as close or very thin looking? I would like to know before investing in the equipment for spraying & after looking as car paint finishes it just looks too thin
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14th June 2014, 08:42 PM #2
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I cant answer your question directly because I spray precat lacquer not postcat (2k) lacquer, however I would like to make a couple of observations:
1. most people who spray lacquer try really hard to get thin-looking finishes. Most people like thin hard-looking coats and say that thick coats look 'unnatural' or 'plasticy'. My own aim is to get the thinnest, toughest finish I can which gives me the right amount of gloss, perfect protection and yet still telegraphs the look of the natural wood through.
2. if you want the best finish possible, forget about 'straight off the gun'. Yep, you can get a great finish straight off the gun, but with a few minutes power-buffing it will be 100% better again, especially to the touch even if it doesn't really look any different. I find it more efficient to spend the time buffing then frigging over the final coat. I'm mainly talking precat, but I cant see why it wouldn't hold true for 2k?
3. if you don't currently have spray-finishing experience, then going straight to 2k sounds like a pretty big step. They are finicky finishes that require a specialised environment, personal protection etc. Precat might be a good intermediate step.Apologies for unnoticed autocomplete errors.
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24th June 2014, 07:19 PM #3
as poster above says...if you are nw to spraying, stepping straight to two pack is probaly a step too far.
If you stuff up using precat nitro, you can simply wipe it all off with a thinners soaked rag...or there may be several other means of rescuing the problem..
Nitro while it can be very thin can look 4 feet deep if prepared an applied correctly.
A great many who are using nitro ( precat) do so because it is very fast...very very fast and it can be slashed over quick and thin.
However if you are looking for a piano finish......more commitment and nitro will get you there....and in good weather 6 to 8 coats a day.
back in the day that is what all the hot rods where finished with nitro but in colour.
cheersAny thing with sharp teeth eats meat.
Most powertools have sharp teeth.
People are made of meat.
Abrasives can be just as dangerous as a blade.....and 10 times more painfull.
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2nd July 2014, 09:19 PM #4
I've sprayed a bit of clear precat nitro at home, and the odd acrylic clear coat over colour. I'm no expert, but I've gone through more than one 4 litre tin over quite a few projects. I've never been happy with the finish straight out of the gun. I've gone for the sand and polish route, which is a lot (lot lot lot) of work, but gives a superb flat shiny finish. Straight off the gun, it's shiny, but rippled. It doesn't come out of the gun as smooth as a good poly brush finish.
Good things come to those who wait, and sail right past those who don't reach out and grab them.
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3rd July 2014, 12:07 AM #5
If you are spraying nitro and can not get a finish better than brushed polly....you are doing it wrong.
If you have a 100% choked out finish, you should be able to achieve a near glass like finish off the gun with nitro.
A lot of people get too timid with the thinners when spraying nitro...it is not unusual to be sprayng more thinner than nitro...25% product and 75% thinner is not unusual.
You can not thin poly that far without problems....thin polly too far and it can tend to go milky and you compromise the resin.
Nitro like shelac is a fi ish that cures more or less by evaporation alone..as such there is more or less no limit to how far it can be thinned.
cheersAny thing with sharp teeth eats meat.
Most powertools have sharp teeth.
People are made of meat.
Abrasives can be just as dangerous as a blade.....and 10 times more painfull.
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3rd July 2014, 10:46 AM #6
I was talking about a high-build finish. Nitro is shiny, but is not flat, and the more coats you lay, the bumpier it gets. You have to cut it back and polish to flatten the bumps out. I guess it's true that the same happens with poly, but on a flat surface, you can brush on a thick coat of poly and get a flat high-build finish in one big final coat, but I haven't been able to do the same with nitro.
Spraying 75% thinner would take an awful lot of coats to get a high build nitro finish!Good things come to those who wait, and sail right past those who don't reach out and grab them.
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3rd July 2014, 07:06 PM #7
come and look at my lounge sweet.
you can build nitro into a fairly high build finish and fairly fast..its all about preparation....and using lots of thinners is what it is all about...12 coats in a day is far from unreasonable in warm weather.
Ever heard of a "piano finish".....before the days of modern two pack laquers, nitro was how it was done.
A mate of mine trained as a piano technician and restorer...when he was at college, they could lay up 6 coats of nitro, in a day, in Melbourne, in winter.
Again thinn is what it is all about...if you do not spray it thin it will not self level...AND like all good finishes its all about the preparation.
If you want a good flat and highly glossy finish right off the gun on the last coat...you need to spray thin and you need to have achieved a good flat fully choked out finish right from the base coats.
OH BTW...you do not need a lot of build to achieve a flat and highly glossy finish.
In fact if you want a realy deep lustre, showing the full beauty and light of the timber, a high build finish is exactly what you do not want.
remember unlike many modern finishes, nitro is not a high build plastic coating..and it should not look like it.
cheersAny thing with sharp teeth eats meat.
Most powertools have sharp teeth.
People are made of meat.
Abrasives can be just as dangerous as a blade.....and 10 times more painfull.
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3rd July 2014, 07:44 PM #8
I will certainly try it with lots of thinner next time. The tin said 5% - 10%, so that's what I used in the past, but I'll see how it goes with more.
Good things come to those who wait, and sail right past those who don't reach out and grab them.
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3rd July 2014, 07:57 PM #9
yeh the tin always says 5 to 10%..on pretty well all paints and varnishes.
Nitro is another strory all togehter......never tried spraying it that thick.
cheersAny thing with sharp teeth eats meat.
Most powertools have sharp teeth.
People are made of meat.
Abrasives can be just as dangerous as a blade.....and 10 times more painfull.
-
10th August 2014, 10:43 PM #10
New Member
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- Nov 2010
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- Perth
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- 6
Hello All,
I find myself in a similar position to tegmark, and in search for the perfect finish. I have resorted to rubbing out a finish after spraying has cured to give the (what I think) perfect look and feel to projects. But have come unstuck with not "Fully chocking" the project first. Leaving powder in the open pores of timber, ie Jarrah.
To fully choke when spraying is to seal the piece with precat 2 or 3 coats and sand between coat down to timber again. Is this correct? From there you then spray and build up your top coats.
I have always thinned the precat down considerable and sprayed about 3 to 4 coats. and rub out to satin or semi gloss finish.
Regards
Gabriel
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10th August 2014, 11:43 PM #11
The big problem you will have with thin sprayed finishes is getting a full choke on porous timbers like jarrah.
Sprayed finishes will generally not flow into holes...there realy is no substitute for rubbing it in, either the finish product or some other grain filler.
Then you have the problem....if you have used a disolved finish like nitro as your grain filler......yeh you can.....if you are heavy handed with the following coats.....the underlying finish will redisolve and air bubbles can come out of the grain......coats later.
there are some devious means to solve these problems.
most finish manufacturers make sanding sealers compatable with thier top coats.....these products usually contain more solids ( to fill the holes) and sand more redily
Build your base and choke out with these rather than top coats.
one trick to stop the bubbles is..... warm the piece well, before you spray and spray light coats.
The coats will tend to go off faster..and if there is reliquifying, the cooling will tend to suck the bubbles down.
cheersAny thing with sharp teeth eats meat.
Most powertools have sharp teeth.
People are made of meat.
Abrasives can be just as dangerous as a blade.....and 10 times more painfull.
-
11th August 2014, 11:37 AM #12
GOLD MEMBER
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- May 2003
- Location
- Central Coast, NSW
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- 611
Soundman has basically answered your question so I hope I'm providing something useful not just repeating his comments.
Basically, what you are doing is trying to use finish coat as a grain filler. Not a good idea.
use a grain filler as a grain filler
use a sealer as a sealer
then use the finish coat as the finish coat.
They are engineered to different jobs.
Applying repeated layers of pre-cat finish coat and sanding them back to get a smooth finish is possible but its doing things the hard way. Precats are not meant to be sanded - there is a small cross-linking effect as they cure which is designed to give a very hard, abrasion resistant finish. This resists scratching and scuffing when the article is in service - but sanding is abrasion as well so a side effect is that sanding is difficult as well. Much better is to fill the grain with something designed to fill grain, and to be sanded off easily. Timbermate is a good choice - make it up into slurry with water and a microwave oven.
Once you are happy with how the grain is filled, move on to the next step. Seal the timber. I know a lot of people don't use a sealer and its perfectly possible to get a good result that way, its just doing it the hard way. Whatever top-coat you are using will have a sealer as a companion product. Use the sealer because it will be:
cheaper then the topcoat
ridiculously easy to sand
quicker drying
generally more fault tolerant in application then the top coat.
Then sand the sealer back. And yep, you will be pretty much back to timber at this point. I like to think of the grain filler and the sealer as taking care of the timber below the surface and the top coats as taking care of the timber above the surface. Understand that there is not a lot of sanding involved - one or two passes with 400 grit is all it should need.
Then apply the top coats. The manufacturer of your product will have a recommendation of how many top coats are usually needed - its probably 2 or 3 - so if you find yourself differing from this number then you need to ask why - somehow you are not using the product as its intended to be. You should not be sanding the precat top coats unless you stuff up - it should come off the gun smooth to the point where frigging with the surface doesn't help.
A few days later you can buff it - but buffing should basically be optional, depending upon the surface you want.
I like to think of the point where you finish sanding back the sealer as the main quality gate in the finishing process. The surface should be dead silky smooth to the touch at this point. If there are any faults, you fix it now (below the surface) before going on to the topcoat. In effect, you are applying the top coats to a perfect surface, not expecting the top coats to do any filling, smoothing out or building up, because they are not the best product to do any of these.
cheers
ArronApologies for unnoticed autocomplete errors.
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11th August 2014, 10:20 PM #13
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- Nov 2010
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- Perth
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Thanks Aaron, soundman.
I will be getting some sealer in the next few days. I have never sealed my precat sprayed projects as was advised by rep the precat didn't require it.
I do use timber mate and water it down and smooth out over projects using a spatula. I have always found the sanding back annoying as I would go through the sand paper like toilet paper and the timber would start burnishing more than effectively sanding.
I can also get a good finish of the gun and will do 3 coats for this. The extra coat to be able to rub out the finish so I am lead to believe! I like to get the smooth feel afterwards and this is when I run into the problems of clogging up the pores with fine dust (revert back to solution A - filling) by rubbing out the finish.
I think I should be just buffing and not the whole rubbing out process. Is this correct?
Regards
Gabriel
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11th August 2014, 11:48 PM #14
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He's right - its not 'required' - but my point is it makes the process quicker, easier and cheaper. This applies especially when you are sanding. A good sealer will sand like a dream and wont clog up sandpaper. Precat is a pig to sand.
Generally, have a look at the documentation that accompanies your product. If the manufacturer recommends a sealer, then they do so because they want you to get the best result out of their product and come back to buy more, so you can be reasonably confident that you should be using it.
Perhaps try rubbing the excess timbermate off when its a little bit dry with hessian. Also, maybe start with coarser sandpaper. Also, are you clear coating - if not then there are many quick, easy-sanding fillers you could be using rather then Timbermate.
Try both and see. The whole rubbing out process is time consuming and profit destroying so if you can avoid it and just do a quick machine-buff then all the better. When I did my previous answer I overlooked the fact that you are after a matt or satin finish. For most things I want a gloss finish so I just do a quick rub over with 1200 grit to knock off any dust nibs etc, then machine buff with Meguiars Fine-cut Cleaner, which despite the name is just a very fine automotive cut and polish with no nasty silicon.
Regards
ArronApologies for unnoticed autocomplete errors.
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12th August 2014, 12:42 AM #15
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I like that Aaron - quicker, easier and cheaper.
I will give the wipe off a go on next project. I have a few project approaching finishing stage. Yes I am clear coating, mostly 50% gloss.
I am trying to fine tune all of the finishing process as this is where I get stuck, time wise. The two issues being the filling and then the buffing/ rubbing out. These are linked together I see along with "choking out".
As you put it, time consuming and profit destroying!! These two areas had been giving me the most amount of grief. Thinking, how in the hell do commercial guys do this and still make money??
Regards
Gabriel
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