Thanks richie00boy. The machine polisher I tried was quite heavy duty and generated a lot of heat. I've abandoned that - hand polishing should be do-able since its just a small pair of bookshelves.
I did slightly damp the cloth, after you post I retried with a more damp cloth and I think that improved things.
Thats a really helpful link GM. I might try filling the swirl marks once I've got the best finish I can; can't hurt to try.
What I've found is that polishing is a bit more of an art than I was expecting,
- Make sure cloth is damp enough
- How much sanding is needed
- How much compound/polish to apply
- How hard to rub
- How long to rub for before switching formulas
etc
And the tricky thing is figuring out the cause of cloudiness/faint scratches/swirls.
I guess it takes a lot of experience to achieve near perfect finishes. At least I've so far managed a stunning finish in all but the harshest bright light reflections from close up.
Thanks for the advice, I'll post decent pictures of the cabinets once finished.
I did slightly damp the cloth, after you post I retried with a more damp cloth and I think that improved things.
Thats a really helpful link GM. I might try filling the swirl marks once I've got the best finish I can; can't hurt to try.
What I've found is that polishing is a bit more of an art than I was expecting,
- Make sure cloth is damp enough
- How much sanding is needed
- How much compound/polish to apply
- How hard to rub
- How long to rub for before switching formulas
etc
And the tricky thing is figuring out the cause of cloudiness/faint scratches/swirls.
I guess it takes a lot of experience to achieve near perfect finishes. At least I've so far managed a stunning finish in all but the harshest bright light reflections from close up.
Thanks for the advice, I'll post decent pictures of the cabinets once finished.
Hello all,
I have a problem with my finish...I'm going for a high gloss black using a pre-catalyzed lacquer, and I'm spraying with a 4 stage Graco turbine with a 1.4mm tip.
So my problem is, it seems to be drying as soon as it hits giving me a very dull and rough surface. And I'm not sure how to correct this, the guys at the shop where I got my lacquer mentioned not to thin it, but maybe that's the answer? Could there be too much air coming out of the gun? I get a nice fan pattern so I assumed everything was okay, but I'm still pretty green when it comes to spraying so any help would be greatly appreciated!
Thanks in advance!
Tristan
I have a problem with my finish...I'm going for a high gloss black using a pre-catalyzed lacquer, and I'm spraying with a 4 stage Graco turbine with a 1.4mm tip.
So my problem is, it seems to be drying as soon as it hits giving me a very dull and rough surface. And I'm not sure how to correct this, the guys at the shop where I got my lacquer mentioned not to thin it, but maybe that's the answer? Could there be too much air coming out of the gun? I get a nice fan pattern so I assumed everything was okay, but I'm still pretty green when it comes to spraying so any help would be greatly appreciated!
Thanks in advance!
Tristan
Is your turbine a HVLP model, and are the paint instructions for HVLP or conventional spraying? I once accidentally set up my compressor to conventional pressure with a gun designed for HVLP spraying. The results weren't great 
.
I understand turbines can make the air very dry (vs. compressors). Are you spraying in a particularly hot and dry environment?
.I understand turbines can make the air very dry (vs. compressors). Are you spraying in a particularly hot and dry environment?
I use a Graco / Croix HVLP cup gun with a 3 stage turbine. By definition if it's a turbine its HVLP.
I use a 1.2 tip and get GREAT results.
Here are some questions you have to answer to determine why you don't get a gloss lay.
How far away from the surface are you holding the tip of the gun?
Should be ~8" or so.
What is the temp. and humidity?
Higher temp and humidity can cause problems.
Hi temp = atomized paint / lacquer whatever, drying on the outside of the little paint droplet before splatting on the surface of what your painting.
Higher humidity = blotching or white ish / blue ish discoloration under the paint being sprayed.
Do you have your air turned up all the way?
Don't. Throttle it down to about 1/2 (or less) for starters
Are you spraying multiple cross hatched (tic tac toe pattern) to achieve the build thickness you want?
You want to spray multiple cross hatched layers, keep it light or you'll get runs.
What is the base coat?
What is the material? ie; hard wood / soft wood / MDF ?
Are you spraying in the shade? Is there air movement? like a fan nearby?
Tell us more about your spray details.
Is the paint flashing off (surface drying) immediately?
If so, then it SHOULD be thinned. Try 10% to start with. Use the CORRECT thinner!!!
We can help.
Ron
I use a 1.2 tip and get GREAT results.
Here are some questions you have to answer to determine why you don't get a gloss lay.
How far away from the surface are you holding the tip of the gun?
Should be ~8" or so.
What is the temp. and humidity?
Higher temp and humidity can cause problems.
Hi temp = atomized paint / lacquer whatever, drying on the outside of the little paint droplet before splatting on the surface of what your painting.
Higher humidity = blotching or white ish / blue ish discoloration under the paint being sprayed.
Do you have your air turned up all the way?
Don't. Throttle it down to about 1/2 (or less) for starters
Are you spraying multiple cross hatched (tic tac toe pattern) to achieve the build thickness you want?
You want to spray multiple cross hatched layers, keep it light or you'll get runs.
What is the base coat?
What is the material? ie; hard wood / soft wood / MDF ?
Are you spraying in the shade? Is there air movement? like a fan nearby?
Tell us more about your spray details.
Is the paint flashing off (surface drying) immediately?
If so, then it SHOULD be thinned. Try 10% to start with. Use the CORRECT thinner!!!
We can help.
Ron
It is HVLP and the gun and turbine are both a system so they should play nice.
It's MDF sealed with shellac and sanded to 220.
I'm holding the gun pretty consistently at 8 inches(or so), but not greatly higher or lower.
The air on the gun was half way, but the turbine has, and I just looked at this today, essentially an 'overdrive' at the turbine for spraying thicker coatings and that was on so perhaps this was my issue...
It was also hot by Edmonton standards yesterday, about 26C or so, and a bit muggy. And I was not spraying in the shade..so perhaps a number of problems plague me haha.
What would you recommend I thin the lacquer with? It was flashing off as you say, it was essentially dry to the touch immediately, it came off on my fingers a bit, but as dust primarily I would say.
It's MDF sealed with shellac and sanded to 220.
I'm holding the gun pretty consistently at 8 inches(or so), but not greatly higher or lower.
The air on the gun was half way, but the turbine has, and I just looked at this today, essentially an 'overdrive' at the turbine for spraying thicker coatings and that was on so perhaps this was my issue...
It was also hot by Edmonton standards yesterday, about 26C or so, and a bit muggy. And I was not spraying in the shade..so perhaps a number of problems plague me haha.
What would you recommend I thin the lacquer with? It was flashing off as you say, it was essentially dry to the touch immediately, it came off on my fingers a bit, but as dust primarily I would say.
Trist,
Great! We're almost there! You've eliminated some of the problems already!
Lacquer dries very fast by it's nature, so expect that. Cut your material by 10% with lacquer thinner, this will produce a thinner coat and will require additional coats. So don't expect to lay down a perfect coat after 4 or so layers. Be careful not to "sand through" the layers, you just want to knock off the dust "nibs".
Practice on scrap material (same type of wood) until you get the hang of how much product you can lay down before a run happens. When you do get runs (and you will) don't panic and don't F with it until it has completely dried, it only make is harder to repair.
Here's a tip.
Watch some of Charles Neil finishing video's on Youtube. He is entertaining and knows his shisnet.
Be patient with yourself, each material you spray will be different and each weather pattern will make the results different too.
With practice you will be able to spray inside a garage while it's snowing outside or when its 100*F . It just takes practice. Don't be afraid to waste some product trying different approaches.
We like pictures, BTW.
Ron
Great! We're almost there! You've eliminated some of the problems already!
Lacquer dries very fast by it's nature, so expect that. Cut your material by 10% with lacquer thinner, this will produce a thinner coat and will require additional coats. So don't expect to lay down a perfect coat after 4 or so layers. Be careful not to "sand through" the layers, you just want to knock off the dust "nibs".
Practice on scrap material (same type of wood) until you get the hang of how much product you can lay down before a run happens. When you do get runs (and you will) don't panic and don't F with it until it has completely dried, it only make is harder to repair.
Here's a tip.
Watch some of Charles Neil finishing video's on Youtube. He is entertaining and knows his shisnet.
Be patient with yourself, each material you spray will be different and each weather pattern will make the results different too.
With practice you will be able to spray inside a garage while it's snowing outside or when its 100*F . It just takes practice. Don't be afraid to waste some product trying different approaches.
We like pictures, BTW.
Ron
Better results today, still not perfect but getting there. Didn't want to make all the changes at once so essentially just went one at a time. I'm getting a little bit of orange peel but there's a gloss to it now, and it feels like lacquer...not like I spat on my speaker then kicked dirt on it..
Lowering the air at the turbine, made the biggest difference, I also tried a few different needles and seemed to get the best results with a 1.3mm tip. Didn't thin it, I thought I had some lacquer thinner left over from a previous job but couldn't find it... so that will be my first stop tomorrow morning and now that I think I'm getting a better feel for how it all comes together I think that might get me the result I'm looking for..
Thanks for the help so far, it's very much appreciated! I'll bring my camera tomorrow as well and take some pictures of the process as well, warts and all so others can hopefully learn from my mistakes.
Lowering the air at the turbine, made the biggest difference, I also tried a few different needles and seemed to get the best results with a 1.3mm tip. Didn't thin it, I thought I had some lacquer thinner left over from a previous job but couldn't find it... so that will be my first stop tomorrow morning and now that I think I'm getting a better feel for how it all comes together I think that might get me the result I'm looking for..
Thanks for the help so far, it's very much appreciated! I'll bring my camera tomorrow as well and take some pictures of the process as well, warts and all so others can hopefully learn from my mistakes.
On the topic of dealing with butt joins in MDF, I've done quite a bit of experimenting, trying different strategies. The veneer method is good but leaves you with sharp edges that you might not want. What if you want butt joins AND roudovers? What I've found to work is quite labour intensive, but it involves first applying two part bog that is reinforced with fibreglass - available at automotive suppliers. Very important to apply it with enough hardener and also in temperatures that are not too low, or you run into problems with sanding it, even a month after applying. 15 degrees C minimum. Then you sand it smooth and apply 2 part bog over to smooth it out, then sand. Next you paint on (or ideally spray) fibreglass resin to the entire inside and outside of the box. Or even better, apply bitumin rubber to the inside as damping, first with a primer coat then successive coats mixing 6mm screenings in - this is for damping as well as sealing the box. The idea behind this is to now lock in the moisture by waterproofing the MDF, to keep it stable. Now prime and paint. Apply a guide coat over the primer then sand it all back until you see none of the colour left. Any that you find is showing all the dips, so you fill those with stopper putty, a very smooth putty intended to go over paints. It's very easy to work with and if you have brush marks from the resin, then you might just about be icing the whole cake with it. Fortunately it's easier than 2 part regular bog and fibrefill.
Even doing all the above you can still get a slight butt join seam coming through, you have to be quite meticulous and not in a hurry. If a seam appears you might have to repeat some steps in further layers.
Now it's been suggested by a commentor on my blog to use epoxy rather than polyester based fibreglass resin. It's stronger.
All this is a pretty extreme effort!
Even doing all the above you can still get a slight butt join seam coming through, you have to be quite meticulous and not in a hurry. If a seam appears you might have to repeat some steps in further layers.
Now it's been suggested by a commentor on my blog to use epoxy rather than polyester based fibreglass resin. It's stronger.
All this is a pretty extreme effort!
Yep. It's a PITA... and that's a lot of work!
The only thing I've found to work really well is to use a 2-part urethane based automotive paint called IsoLack. The first few coats will just disappear into the MDF 'end grain', but after letting it dry, then sanding, it appears to stabilise it sufficiently that several more paint coats will then work. I think the product has a slight elasticity, which may help.
The problem of course is that 2-part auto paints are nasty and very dangerous to spray
.A friend of mine used some epoxy paints (used for model aircraft) and that seemed to work on a small test block, but I understand the paint is very expensive.
A US builder here reported good results using a 1-part urethane floor enamel by (I think) ArmorSeal, followed by a water based colour coat. The problem is that the ArmorSeal product isn't available in the UK, so I can't test it. I understand the formation of MDF is different in the US to the UK too - so that may have a bearing. If it worked though it'd be ideal as it's all relatively safe stuff to use.
One useful idea is to remember to keep the unpainted boxes in their ultimate destination for some weeks before painting - so they have roughly the right moisture content before they get sprayed.
I'd suspect the latter would be better. I'm sure a touch up gun would work, but the cups are generally also small, as they're not really intended for painting 'large' areas (i.e. even a small speaker cabinet).
The info sheet that comes with the paints you use should advise on pressures and suitable tip sizes.
Hye guys,
I am going to build a small paint room in my garage/storage with an exhaust fan. Pretty much for one speaker at a time. I will use a mover's dolly to spin the speaker around so it will be a one side paint position for the most part. Any tips? Have you guys built paint rooms?
Also I am thinking about sticking to spray cans first but I might consider a budget spray gun. Any recommanded bundget spray guns out there (USA)?
I am going to build a small paint room in my garage/storage with an exhaust fan. Pretty much for one speaker at a time. I will use a mover's dolly to spin the speaker around so it will be a one side paint position for the most part. Any tips? Have you guys built paint rooms?
Also I am thinking about sticking to spray cans first but I might consider a budget spray gun. Any recommanded bundget spray guns out there (USA)?
Make sure you either use waterbased products only or select a fan with brushless motor. Solvent paints and brushed motor is an explosion risk.
Having a spray setup I would never go back to cans, but if you are only building a set of speakers the investment is probably too much. But then again you must be planning more if you are building a spray room?
Having a spray setup I would never go back to cans, but if you are only building a set of speakers the investment is probably too much. But then again you must be planning more if you are building a spray room?
As Rich noted - there is an explosion risk with solvent paints and an unsuitable fan.
I'd personally also be worried about spraying in an enclosed space (even with an exhaust fan) without some form of air feed. Just too much risk of breathing in stuff you really don't want hitting your lungs.
I'd love to set up an indoor spray booth, but wouldn't consider it unless I could get a clean air feed. The problem is that most small compressors I've seen don't have the capacity to run both a gun and an air-fed mask.
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