View Full Version : Looking for a glassy finish
Novice Jeff
22nd January 2008, 10:44 AM
Hi,
I have an old, solid, Queensland maple cabinet I am doing up, and after reading lots of postings on this site, I decided to use Cabots Gelclear Gloss - polyurethane. I have sanded down the whole cabinet, down to 600 grade, and it looks great.:)
Have put 4 coats on with sanding in between. I am using a brush and am hoping I can get it to glassy finish. But so far it still has lines in it - brush marks.:~
Do you think it is possible to get mirror finish using brush and Gelcoat?? Is there something else I should be doing??
Any advice appreciated - Jeff
ciscokid
22nd January 2008, 10:50 PM
Hmmmmm. You could try an experiment on a piece of scrap. Try wiping the finish on with clean cloths. It takes longer to build up a finish, but I don't get lines when I do it this way. Best of luck!
Novice Jeff
23rd January 2008, 09:27 AM
Thanks - I'll give this a try. I have also read about the EEE on the forum, and maybe I'll try cutting the finish back with that when I have have a few more layers on. Maybe that will polish any imperfections out.
munruben
23rd January 2008, 10:43 AM
If you have brush marks in your work you are not going to get rid of them by applying more finish with a brush. You really have to sand the brush marks out between coats to provide a smooth surface for the next coat. Is it warm enough where you are doing your work? Temperature can have a bearing on your finish like brush marks if it is too cold. I would do as ciscokid suggests and try using a cloth to apply the finish instead of a brush.
Might be an idea to have a look HERE (http://www.ubeaut.com.au/ubhome.htm)and read about Traditional Wax as a final process if you want a really great finish to your work. Good luck
Novice Jeff
23rd January 2008, 11:32 AM
Thanks John,
Have just sanded out all the brush marks (whew!!), and put a coat on with a cloth. I can see it will take a few coatings this way, but it does look a smoother finish.
Temp here should be OK - am not far from you in Brissy. Probably trying to put too much on with each coat using the brush. The gel is pretty thick and it feels like you have to load up the brush to get coverage.
Looked at the traditional wax info, and I will probably try some of that when I have put more coats on.
Thanks for the advice.
Jeff
starr
23rd January 2008, 12:52 PM
To get a smooth finish I wet sand between coats. Start with 320 grit wet and dry paper after the first coat and wet sand, using a little soap in the water. Wipe off any residue. Recoat and use 400 grit this time. Repeat using 600 grit. By the end it should be as smooth as a baby's bottom, but won't be a gloss finish if that's what you are after.
If you want gloss, you can use car polishing products (Mequires is probably best) with a sheep's wool pad on an polishing disk in your drill to really bring out the shine.
durwood
23rd January 2008, 07:19 PM
To get a realy glossy finish you have to have a few things going for you.
First if the material is too thick it will set up before it has time for the brush marks to flow out. so you may have to add some turps to reduce the viscosity. Take it easy it will only need a tiny amount ( you can always add a bit more harder to take it out)
You will need a good pure bristle brush and the temperature needs to be in the mid twenties. too hot and the paint will dry too quickly too slow as Munruben says tends to stop it flowing out also.
Practice on something first, and apply a full wet coat with the brush just get it on quickly) once the area is covered then wipe out the excess paint and lightly wipe the surface with the tip of the brush along the length of the panel. It should be still wet enough to allow the brush marks to flow out before it sets up. If the surface is vertical finish your brush strokes up and down not across ways.
There is no need to use as fine a paper as you are using 240 in more than smooth enough ( the material will easily fill the scratches left by it) but before you brush any surface it must be smooth. The next coat won't be able to handle any faults left in the previous coat it can only become perfectly flat if it is on a surface which is also flat. Tiny variations sometimes come out but if you knew they were there and they didn't come out you immediately know you should have rubbed a bit more.
Done properly it is impossible to tell if the surface is sprayed or brushed, it just takes a lot more effort to brush a perfect finish than spray one.
Novice Jeff
23rd January 2008, 08:46 PM
Thanks for the advice,
Must admit to some frustration - feel like I have sanded off more than I have put on!!!!
Have sanded wet with 600 grade, so got the surface smooth as glass. But putting the gelcoat on, both with brush and cloth, has proved difficult. I think you are right that it needs thinning - I think it is drying out too quickly. Just not sure about thinning the gel product. Will have a go tomorrow.
Thanks again
jeff
MacS
24th January 2008, 11:07 PM
Jeff,
The more coats you keep applying on the piece, the greater the odds that the coating will eventually start cracking. You need to allow the coating to dry for at least 72 hours
There comes a time that you have to start rubbing out and polishing it up to bring out the gloss in the coating.
Is the "gelcoat" your using a gloss, satin, or flat. Read the label, some gelcoats are not intended to be altered, the way they dry is the way they stay.
Good Luck
manoftalent
24th January 2008, 11:53 PM
umm.....I may be tired ....but was'nt there a product called "glass coat".....that when applied was =to 50 coats of poly?......I am sure I read it here some time ago, and if memory serves me ....bunnies has it ..
Novice Jeff
25th January 2008, 09:43 AM
Thanks,
The Gel coat is gloss - and I don't think I'll thin in down. Have rubbed back again to "glass" finish, and I think I'll try some traditional wax on it now. I have a buffing pad for angle grinder and see if I can buff it up with the wax.
Thanks for the tip about "glass cote". Will see if I can find out more about that as well.
Cheers
jeff
Cruzi
25th January 2008, 11:12 PM
Angle grinders are waaaaaaay to fast for polishing, they go around 10,000rpm, you need a polisher if you are going to buff the piece, most go between 900-3000rpm, much safer for polishing.
Also read that if looking for high gloss finish, the longer you allow the finish to cure before rubbing the final gloss the better, 2-3 weeks minimum.
MacS
26th January 2008, 12:07 AM
If professionals had to wait that long, they would go out of business.
That's OK, if your getting the real big bucks for your work, or its for yourself and you have plenty of time.
Also, it depends on the coating your using.
Cruzi
26th January 2008, 01:19 AM
If professionals had to wait that long, they would go out of business.
Thats why most commercial furniture is finished in satin.
The book reasons that the finish should be fully cured to get highest gloss, with polys this is usually 2 weeks, with shellac its about 6 weeks
You can get a gloss finish much quicker, but its not as long lasting or glassy.
It didn't sound like Novice Jeff was doing a commercial production run, rather a restoration at home, don't think production efficiency is a high priority.
artme
26th January 2008, 07:28 AM
At one stage I considered myself to be the world's worst finisher when it came to "painting" on a finish, be it with a brush, a roller or anything else.
however advice from those with experience taught me this:
Don't work the finish too much, because it will start to "go off before you are done.This leaves ugly marks.
Work quickly and smoothly
For "varnish type" finishes a Lambswool applicator is often the best solution.
Try o have the surface you are working on in a horizontal poition as this will give the finish a better chance to level itself.
durwood
26th January 2008, 07:36 PM
I'm surprised MacS hasn't followed up this yet.
Gloss has nothing to do with drying time or life expectancy.
A finish will gain its maximum gloss when it is applied. If you look at instructions for application of a finish on a tin or even on a technical data sheet for a professional finish you will rarely see instructions on how to get a gloss its intended that the a painter applies it properly to achieve full gloss ( lacquers are the exception they only reach about 80% gloss and require buffing) Normal paints are sold and labeled as gloss finish If you have to then rub, compound polish wax or what ever you have not quite made the grade with the finish.
Why do a lot of things come with a satin finish? because full gloss shows up far more faults than one with less gloss. You can have small imperfections in the surface or dust particles and they are a lot harder to see. From a consumers point of view gloss surfaces finger marks dust and other problems more easily to see so less gloss is favoured by most people and the manufacturers. If you asked for gloss you would be paying a lot more.
Professional finishes as MacS says need to be applies and passed on to customers quickly. Finishes available in normal outlets are designed for the non professional who will probable use a brush, roller or other method besides spray. Thse finishes are designed to dry slow and can take a long time to go completely hard. Attack them too soon and they dull off as solvent will continue to leech out and dull off the finish or be soft enough for the rubbing to affect the surface, buffing may create enough heat to make the finish sticky and get burn marks. These finishes never were designed to be rubbed back and then made to produce a shine. Any gloss you get will not be as good as the original when it was flowed onto the surface. Waxes and polish are designed to get you up to a better gloss level but its them that shines not the paint surface.
A 2 pack polyurethane used in industry dries too hard if left for more than a day in normal temperature ( and can be baked to dry in minutes) Leave it for a week and try to rub it or do some other gloss producing process such as machine buffing and you will get a result that is similar to trying to removing scratches out of glass the paint is so hard. The life of these finishes is at least 20 years.
You may have noticed that paint finishes on motor cars are not very glossy ( usually has orange peel or worse) unless it is the top of the line vehicles. To gain that mirror finish you are on the verge of the paint running so the car companies err on the side of caution, better to have a bit of peel than have to rub it down and put it through the line again.
The paint used to repair them these days is so good spray painters usually have to mix the paint and apply it badly to match the rest of the car, where they could if they wanted to apply it far glossier.
These paints also dry very rapidly, by using different hardeners and thinners they can be applied and the car owner can take them home in the rain in less than 1/2 hour and the gloss can be perfect.
Chemists working in the lab have it easy, they usually do all their work on small 6"x4" plates so its a breeze to get a perfect gloss.much harder when the areas are large or worse still vertical but they are designed for the idustry to use quickly or businesses would go bust. The main reason 2 packs are used is that they eliminate to need to polish after application, this saves hours and days in labour.
Want to get a perfect gloss quickly?
Spray the finish on in a dust free environment making sure there is no chance of contamination getting onto the surface once its applied.
Make sure the spray equipment you use is correct and adjusted properly for the paint type you are applying.
Make sure the surface to be covered is perfect with no faults in it or the gloss will show them up.
Ensure the finish is a top quality finish designed to apply and obtain 1st class results not something from a hardware store. Then mix it to the correct viscosity with the right thinner and hardener so it will be able to flow out into a mirror finish.
And of cause apply it correctly. If you can't do this then you will have to rub ,buff and polish it but it wasn't sold with that being a part of the process.
Do it right and you will get the best result possible, after that anything you do will detract from that finish even wiping it with a solf cloth.
Everything touching the surface will marr the gloss even a sweaty finger.
It is possible to get a prefect finish with a brush but it takes a lot longer and is a lot harder to do.
MacS
3rd February 2008, 12:50 AM
Durwood, I agree, as long before there was spraying there were mirror finishes.
Today, there are still some shops that only do hand finishes, there are some other shops that says they do hand finish, whereas, all the coatings are sprayed, but their final finishes do come from hand rubbing and polishing.
Consideration, should always be considered in the amount of time that you have to complete your work. by knowing the differences in the drying and curing time of each coating you work with can benefit you on which coating would be best for each job.
If you never tried pumice or rottenstone you should take the time to learn, they work on almost every coating, and they definitely will improve your finishing.
astrid
3rd February 2008, 08:24 AM
Does this application advise apply to oil based paint, gloss or satin?
Had to paint a kitchen table black last year.
Getting a smooth finish with a brush was a real bi ch.
This should help for next time:)
Thanks durwood and cruzi, will bookmark this one.
Astrid
Toyboy
3rd February 2008, 08:50 PM
To get a professional 'gloss' finish, use a short pile roller. Apply the finish with a brush as usual and then roll over the surface. After applying a few coats, I would not reccommend any more than 3 or 4 coats, there is a water-based duco cutting polish (about $175.00 per litre) that can be used with a polisher.
It can be rubbed by hand, but it really is hard work this way.
If you have a panelbeater mate, he/she may be able to give you a little to use.
Good luck with whichever solution you choose, because they are all very hard work, unless you are set-up with all the gear.