View Full Version : Spray finish...so many things to consider!
buzsaw
15th November 2005, 01:06 AM
OK, first off I wish to thank everyone for there help in other threads discussing spray finishes. I have read them all and learnt so much from the info within. The search tool is a wonderful thing. Especially thanks to Richard Woodhead for his comments and PM.
Anyway, armed with my new found knowledge I decided to give it a go this weekend and apply a two pack lacquer to this wonderful table I had just built. The end result was a little mixed and I have learned...the theoretical concept and the actual physical act are very different.
The base looks great and is complete with two coats of lacquer. The top however has been hidden in the shed and will be sanded back tomorrow night after work. Bloody hell the first coat was brilliant and I thought to my self I am a luck bugger that the result looks so good on my first attempt. The second coat however brought me back to reality. Looks like a piece of poo. Splatter marks, a surface like orange peel and some sections feel like sand paper. Yuck.
So I went back and reread the previous posts and realised there is so much to consider. Anyway, my father in law is a painter, retired now, but came over last night and went through everything again with me. Richard as you say there is no better way to learn then being with some one and having them show you. Anyway I have convinced my father in law to come over next weekend and he will give me some guidence.
He also believes from looking at the result I did not have enough product coming out. Seems right to me also but I think there is more going on. I did not thin it as the thinners I got was not compatible and couldn't get any on the Sunday when I needed it.
So I thought I would share this experience with the group and if someone learns a little quicker then me I will be happy. The main point for me is never be afraid to try new things, it is the only way to learn. I am very happy with the base so I know it can be achieved. When I get there and the finish is brilliant all of this will be worth it. Hell I am enjoying myself at the moment anyway so it is alrady worth it and a little sanding never hurt anyone.
Cheers,
Buz.
echnidna
15th November 2005, 07:37 AM
The lack of thinners was the problem
Richardwoodhead
15th November 2005, 10:52 AM
No thinners, not enough air, not enough product..... any / all these will cause your problems. But for sure the no thinners!!!!!
Richard
buzsaw
15th November 2005, 04:16 PM
Hi Bob and Richard,
Thanks fellas this is the next step in my move towards a great spary on 2 pac finish. I have ordered the thinners and it should arrive today or tmorrow at the latest. Will let you know how the results are when I try again.
This might sound silly but how do you decant the thinners from the 4 litre tin without making a bloody mess every where?
Cheers,
Buz.
Auld Bassoon
15th November 2005, 06:27 PM
Hi Bob and Richard,
Thanks fellas this is the next step in my move towards a great spary on 2 pac finish. I have ordered the thinners and it should arrive today or tmorrow at the latest. Will let you know how the results are when I try again.
This might sound silly but how do you decant the thinners from the 4 litre tin without making a bloody mess every where?
Cheers,
Buz.
This might sound daft, but I use an aero modellers electric fuel pump (impervious to most thinners, but check first!) and just pump it into whatever smaller container is required. BTW, a manual one would do just as well.
So care is needed, however, when switching from, say, Meths, to Turps, or whatever, so I flush the gizmo with a little pure alcohol and make sure it's dry before then next use.
Cheers!
Harry72
15th November 2005, 08:42 PM
This might sound silly but how do you decant the thinners from the 4 litre tin without making a bloody mess every where?
When you tip over the thinners can have the can outlet/screw top thread at the top(12 O'clock!)and the receiving container tilted with its top lip at the base of the cans thread... like pouring a beer sorta.
Its best to do it over the edge of a table, this way as the thinners can emptys the further it can be tilted without the receiving container hitting the table... 1st couple of times it may pay to lay down some news paper on the floor until you get used to doing it.
http://img.photobucket.com/albums/v725/ST170ish/tippingacan.jpg
RETIRED
15th November 2005, 08:46 PM
Hi Bob and Richard,
Thanks fellas this is the next step in my move towards a great spary on 2 pac finish. I have ordered the thinners and it should arrive today or tmorrow at the latest. Will let you know how the results are when I try again.
This might sound silly but how do you decant the thinners from the 4 litre tin without making a bloody mess every where?
Cheers,
Buz.
Get a clean, wide mouthed glass jar. Take lid off thinner tin. Place jar under lip of lid across the widest part of the tin, i.e. over the handle. Lift tin slowly and pour. Do not upend tin, you have to let air in so that it poors evenly, not in "glugs". HTH and that you understand what I am saying.
RETIRED
15th November 2005, 08:47 PM
Bugger, slow typer. Good onya Harry. Great minds think alike.
buzsaw
16th November 2005, 12:54 AM
Harry/,
Thanks for the info, I understand what you are suggesting and will give that ago.
Steve, thanks also for sharing your method. If I was decanting lots of product I would invest in the little pump, clever.
I just finished sanding back the table top tonight. Didn't take too long at just over 45 minutes and only three pads to get back to bare wood. Can't wait to have another go at spraying it. Possibly Thursday and with all suggestions taken on bard.
Thanks again.
Buz.
Richardwoodhead
16th November 2005, 10:38 AM
Buz, a few more thoughts on working with thinners, lacquer...
If you're going to be using a fair amount of thinners, consider buying a 25 litre drum from 22 services. It's cheaper and you get a screw-in tap device for the base of the container. So when you want thinners you just open the tap and it's easy to get the amount you need. (Sit the drum on top of another empty drum to get if off the ground and hence make the tap usable).
I use a stainless steel metal rule "standing" in my pot to measure component parts (lacquer / hardener / thinners). For example, with the Becker Acroma DM 307, I pour in 10 parts lacquer, 1 part hardener then 4-5 parts thinners. Then clean off the rule by wiping with a thinners soaked paper towel.
I also keep a 5 litre tin labelled "dirty thinners", into which I pour thinners I've used to clean out my pot / gun. If you do a fair amount of spraying you could end up wasting a lot of thinners by throwing away the thinners you've used to "wash" out your pot and spray thinners through the gun as a clean out. I was told by the guru at 22 services that this "dirty thinners" (the low toxic stuff sold by 22 services) can then be used as thinners in a subsequent batch of lacquer mix. I've been doing this for a year and have had no problems. Certainly helps saves on thinners, as before I had been throwing the pot cleaning stuff away.
Also, I used to find lacquer mixing incredibly messy. Getting the DM 307 lacquer out of the 20 litre drum was not easy (And it needs stirring before extracting if it's a 30 or 40 gloss lacquer, as you have to re-mix the matting agent, which settles out as a white cloud in the bottom of the tin - full gloss has no matting agent so doesn't need mixing / stirring as much). Anyway, 22 services also sell empty 20 litre drums with a lacquer tap at the base. (Sure beats dipping in cups which get coated in sticky lacquer and are basically useless after one use.) So you can pour your lacquer into this drum and use it to cleanly extract lacquer. (I also went "one better", and collected 10 2 litre glass bottles (ex grapefruit juice containers) and after mixing up 20 litres of lacquer in the drum with tap, I fill up the 10 bottles and store in a box away from light. That makes it really easy to pour in precise amounts of lacquer. And I rinse the bottle with thinners when it's empty (and save the "dirty thinners.... etc)
Just a few operational thoughts. Working with lacquer, thinners, etc can be challenging.
Richard
Cliff Rogers
16th November 2005, 12:19 PM
G'day.
Another 'gotchya' that got me is the air hole in the top of the pot on my set up got some material in it & blocked up.
The result was the air/material ratio went out the window & I ended up applying a very thin, almost completely dry coat.
buzsaw
18th November 2005, 09:16 AM
Richard, Thanks for that...some excellent ideas there which I will adopt. My shed is looking cleaner already :).
Cliff, Yep got caught with that too. Had to crack the lid a little to let the air in :(
Thanks all for your help.
Buz.
normell
18th November 2005, 09:30 AM
Best bet is to put a few sanding/sealer coats on first, sand back with the finest wet & dry, then go for your top coat/s.
And don't try if it's too cold or humid.
Normell
buzsaw
20th November 2005, 12:34 AM
Hi all, Thanks again for your feed back and assistance, the advice was very welcome. I sanded the table back during the week and picked up the thinners on Friday afternoon. With some trepadation I applied a coat of sealer, resanded and then a coat of finish today. Bloody ripper. I am happy with the result and have now converted to spraying. I am still very much a novice here bit can only improve.
Thought I would attach a couple of photos but they don't do the surface justice really. Anyway, thanks again for the help.
Cheers,
Buz.
Richardwoodhead
20th November 2005, 10:04 AM
Good one Buzz, looks very nice! Well done. Once you conquer the "tricky" parts of lacquer spraying, you can achieve beautiful, very durable finishes, in a fraction of the time it takes using other techniques.
What sanding sealer did you use? How did you apply it? I've never used a sanding sealer so would appreciate your comments. Jarrah is fairly open grained, so even after 2 or 3 heavy coats of lacquer, you can still have a "textured" look & feel to the finish. Which I like. How many coats of lacquer did you apply over the sanding sealer? What was the lacquer? Looks like 40% gloss?
Richard
buzsaw
20th November 2005, 10:40 AM
Good one Buzz, looks very nice! Well done. Once you conquer the "tricky" parts of lacquer spraying, you can achieve beautiful, very durable finishes, in a fraction of the time it takes using other techniques.
What sanding sealer did you use? How did you apply it? I've never used a sanding sealer so would appreciate your comments. Jarrah is fairly open grained, so even after 2 or 3 heavy coats of lacquer, you can still have a "textured" look & feel to the finish. Which I like. How many coats of lacquer did you apply over the sanding sealer? What was the lacquer? Looks like 40% gloss?
Richard
Hi Richard, Thanks for the feed back and earlier assistance.
Both the sealer and the top coat are wattyl acid cat, Acid Cat Sealer and Acid Cat Clear Topcot (30% gloss). I followed the instructions and directions from the rep and applied a single coat of each product but a "double-pass". Hope I interpreted this correctly and applied the sealer, waited 3 minutes and then applied another coat directly to it.
Left it for 5 hours, instructions say 1.5 hrs but had other things to do, and sanded it back reasonably heavy to 320 grit. Then applied the top coat using the same doube-pass method. I coated both top and bottom the same although the sanding was very quick on the underside.
Although it is dry in 1.5 hrs the result seems to get better over a few days. I read somewhere in another thread this is called gassing off? There is still a little smell coming from it and the surface looks better this morning but this could be just my imagination ;)
The manufacturers instructions warn against excessive builds for both undercoat and topcoat to avoid stress cracking. I am very happy with the finish now so will not apply another coat.
Cheers, Buz.
Redback
12th December 2005, 12:06 PM
Hi Guys,
Have been reading a few of the threads on sparying lacquer as well.
I am currently building two long craft workbench tables for my wife. The top is jarrah veneered chipboards, 2400 * 600 * 32.
The legs and supports are recycled Jarrah 80 * 40mm.
Anyways, in the past I have only done small jobs and have used shellac and trad wax or EEE. Im now thinking that for a harder surface I need to spray on a lacquer. I was nervous about doing this before hand, but now Im petrified after reading some posts !!
Anyways, to get me started, can anyone give me a couple of recommended purchases...
I have a compressor and a cheap and nasty gun that came with it, but Im guessing I shouldnt use that.
Im thinking of getting the porter cable gun from carbatec (seems a few people use this?)
[PSH2] PORTER CABLE PSH2 GRAVITY FEED DETAIL SPRAY GUN
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Will I need a regulator for this?
Both the sealer and the top coat are wattyl acid cat, Acid Cat Sealer and Acid Cat Clear Topcot (30% gloss).
where did you buy this from? is there specialist dealers or would Bunning have this?
Anyone in Perth willing to give a complete novice a demo!!..
I am really worried about buggering this job up...
Alternatively is there a something safer I can use by hand. I havent tried to test it, but would hard shellac be resistant to scratching etc
cheers
Redback
MurrayD99
12th December 2005, 12:21 PM
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Will I need a regulator for this?
cheers
Redback
I think it will be necessary, otherwise the pressure at the gun will be the full pressure generated by the compressor - which might not coincide with the requirements of the product you are applying. I recently sprayed Wattly Deck & Furniture oil for the first time and made a bit of a mess -
had to reduce the pressure at the regulator to 35psi. Normally, I'd use 60psi for paint. I don't think the sort of gun you use will change the situation - though some guns have pressure control on the grip - but unless you got a guage, that is hit and miss. Good luck.
echnidna
12th December 2005, 02:05 PM
Before you go and get another spraygun try the old one out.
You can always fill it with clean water and just spray you shed wall to see if it give a nice mist. If it works ok with water it should handle lacquer ok.
Richardwoodhead
13th December 2005, 10:04 AM
Redback, unless you're wanting to start down the lacquer road for most of your finishing (in which case this job will be a good learning exercise), there are other easier options for this particular job. The one I would suggest is using an oil/poly mix. The one I've used a lot is Feast Watson Floorseal. It produces a nice satin finish which is water proof and very durable. The best application (in my experience) is to SPRAY on the coats of Floorseal (You can add a little turps as a thinner). And sand back (random orbital / 320 grit) between coats. Two or three coats will do. By the third coat you'll have a beautiful finish. I offer this info only if you want to avoid the sometimes stressful task of mastering lacquer spraying.
Richard
Redback
13th December 2005, 11:44 AM
I just posted a longish reply to this and it didnt post :mad:
Anyways, thanks for the input.
Richard, I was sorely tempted by your recommendation, but I need/want to learn how to spray lacquer. I have many large projects I intend doing in the future and I think lacquer will be the way to go.
Still trying to find where to buy it though. Phonebook has my nearest supplier about 70 k's away...
Couldnt find anything at Bunnings. (sounds too technical from my reading for them to supply!)
Anyways, quick question for you. Was reading an article in Fine Woodworking and it talks about using some kind of paste to filll open pored timbers. I noted you mentioned that Jarrah is an open pored timber. Do you do anything like this, or do you just apply a few coats of sanding sealer?
What grit do you sand your Jarrah down to when its still raw? My side tables etc I was sanding down to about 1500 grit, for applying shellac. I dont want to have to go that far for these table as It will take me a month!.
anyways, thanks for the info.
Redback
Richardwoodhead
13th December 2005, 11:02 PM
Good move. Once you've mastered lacquer spraying it's one of the best finishes around. Quick, durable, lovely satin finish. Etc.
I don'y use any sealers as I like the open grain look & feel. However, after a few coats of lacquer, the build will start to fill most pores.
Mirotone and Becker Acroma are two high end Lacquer sources. I think Wattyl also produce lacquers. The highest quality lacquers (I've been told) are the 2-pack acid curing lacquers. You usually add one part hardener (the "acid") to ten parts of the lacquer. Becker Acroma (a low toxic, high quality lacquer) is about the only product used by all the local SW woodworking galleries (Boranup, Yallingup, JahRoc, etc).
Twenty Two Services are the local distributors, located north of Perth - Neerabup. Speak with Paul Daley. 9206 0220. They also sell high end spray equipment.
I only go down to 180 grit / orbital. Then a light 320 grit sand between coats of lacquer. After lacquering they're smooth as silk.
Richard
martrix
13th December 2005, 11:19 PM
all this great advice, and not one mention of lung protection?
once you get a decent dual face respirator with dust covers, you will see all the crap it catches, and remember that you once used to inhale it!