what do you know about nitro lacquer?

[mistermikev]

so... started working with nitro on my most recent build and I can see why it is so popular.  The stuff I got goes on great and is dry in 30mins w the az climate.  I had some issues with particles landing on it so stripped it back with acetone last night... that was a breeze!  I am probably going to use it a lot going fwd but have some questions...

1) I don't have a respirator... right now I'm spraying outside and holding my breath and backing off of it quickly but obviously this won't do long term... don't want to spend too much so wondering what are options for a respirator on the less-expensive side?

2) safety (I know, asking that while not wearing a respirator!) after stripping I had some paper towels with nitro and acetone on them.  unraveled them to dry for 20 mins, then balled them up and put them in a double plastic bag with a cup of water and tossed them in the trash.  What do you do with yours?  what about storage? 

3) as I mentioned i had issues with eyelashes and general dust from the az wind.  can't spray this stuff in my garage (as I understand) because I have a gas waterheater (spark).  what do you do to prevent dust bunnies from congregating on your finish?

 

thanks in advance for all advice

[ADFinlayson]

I'm contemplating a designated spray area, granted it wont be until I move house - some time later this year or next year. But I'm thinking a cheap way of isolating an area would be a shower curtain type setup, maybe 2 curtains, but I ideally I want to put in a partition wall which would be fairly easy to build with 4x2" and some plasterboard, then have a curtain covering the door. 

I've done nothing with Nitro, but based on the nasties in poly and the cellulose sealer I've been using, I wear a mask anyway. The respirator I use was only about £20 from screwfix (a UK trade/building supplier). Then I'll wear a pair of goggles as well. There seems to be a massive price difference between this approach and the full face masks.

[mistermikev]

2 hours ago, ADFinlayson said:

I'm contemplating a designated spray area, granted it wont be until I move house - some time later this year or next year. But I'm thinking a cheap way of isolating an area would be a shower curtain type setup, maybe 2 curtains, but I ideally I want to put in a partition wall which would be fairly easy to build with 4x2" and some plasterboard, then have a curtain covering the door. 

I've done nothing with Nitro, but based on the nasties in poly and the cellulose sealer I've been using, I wear a mask anyway. The respirator I use was only about £20 from screwfix (a UK trade/building supplier). Then I'll wear a pair of goggles as well. There seems to be a massive price difference between this approach and the full face masks.

the complication with nitro is it is explosive.  I've read that a regular fan can spark an explosion... so setting up a room with a vent is a bit more complicated.  I don't know if they make special fans but I have seen at least one thread on facebook regarding a nitro fire so really want to take it seriously.  the fumes from poly are not something I want to breath... but ime they aren't nearly as unpleasant as nitro.  I spray poly and acrylic all the time in my garage and just shoot quick and get out of there while it dissipates.  I just setup a big cardboard box and seems to work pretty good but the downside is I have to clean the garage before I start anything like that... I spose I should really get a dust collector and keep it clean.

I do like the nitro tho... if you have to strip it it takes all of about 5 mins and it goes on and drys in seconds (at least in az it does)

I noticed the big dif in the face mask too.  looks like you can get one of these smaller ones for under $50 all over the place but the facemasks start over $100.

thanks for the response ad.  I do appreciate it. 

[Bizman62]

I bought a mask from Banggood. On the positive side there's granular activated carbon in the filter which was a nice surprise for $6.50 or so. On the negative the exhaust vent is facing ahead just like on the one shown in the picture. The moist of the exhaust breath condensates and spreads drops all over the place. And since it's Chinese, it doesn't quite fit my European chin.

The workshop they keep our courses in has a professional dust collecting system as well as a painting wall with suction. When the big table saw caught fire I learned that there's fire extinguishing sprinklers in the pipes so the dust collector won't burst into flames.

[mistermikev]

thanks Bizman62... I guess vents at an angle is better then.  Good to know.

tablesaw caught fire... what the devil?

[curtisa]

Probably the more important factor to note is that spray painting using any chemical is considered a hazardous practice. The idea that poly 'smells' more pleasant than nitro should not be used as an excuse to cheap out on the safety gear. Use a respirator rated for use in paint and solvent fume environments. It might cost a hundred bucks and each filter pack good for only 6 weeks at $30 each, but if you're going to expose yourself to known-dangerous vapours then you should be doing what you can to protect yourself.

I would also imagine that all solvent-based sprays are flammable. That would include any of the solvents used to thin them. Again, not a reason to handle poly any differently than nitro.

Spraying in a confined space also serves no benefit if all you're doing is filling up the area with a high concentration of fumes and atomised paint. All that does is put even more stringent requirements on the protective equipment and control of combustibles. Spray where there is ventilation. Depending on your work area, that may mean timing your spraying activities to coincide with the weather.

[mistermikev]

1 hour ago, curtisa said:

Probably the more important factor to note is that spray painting using any chemical is considered a hazardous practice. The idea that poly 'smells' more pleasant than nitro should not be used as an excuse to cheap out on the safety gear. Use a respirator rated for use in paint and solvent fume environments. It might cost a hundred bucks and each filter pack good for only 6 weeks at $30 each, but if you're going to expose yourself to known-dangerous vapours then you should be doing what you can to protect yourself.

I would also imagine that all solvent-based sprays are flammable. That would include any of the solvents used to thin them. Again, not a reason to handle poly any differently than nitro.

Spraying in a confined space also serves no benefit if all you're doing is filling up the area with a high concentration of fumes and atomised paint. All that does is put even more stringent requirements on the protective equipment and control of combustibles. Spray where there is ventilation. Depending on your work area, that may mean timing your spraying activities to coincide with the weather.

all good points.  wasn't intending to imply that poly is not dangerous... just comparably less so afa exposure and explosiveness.  it also sprays so thick that it hits the floor a lot faster.   When I spray it I'm generally doing 1 coat, getting away from it asap, and  opening the garage door a foot.  I know that still means I'm being exposed to it... but I am def minimizing it.  that said... yes a respirator is in my future and a good call. 

so what say you regarding disposal of potentially flamable rags/paper towel?

[curtisa]

3 hours ago, mistermikev said:

so what say you regarding disposal of potentially flamable rags/paper towel?

Lay them out flat, not scrunched up into a ball, on a non-flammable surface (concrete, pavers, tarmac) until dry, then chuck in the bin. Self-combustion is only a risk while drying, and once dry they're no more volatile than newspaper.

[Bizman62]

16 hours ago, mistermikev said:

tablesaw caught fire... what the devil? 

Well, apparently the dust vacuum hose was loose. There was some dust inside the saw and a younger and less experienced me was splitting a very hard piece of maple with the blade too high. The friction made the sawdust glow and... When smoke arose, someone got the fire extinguisher and emptied it into the saw. After cleaning no other harm done, "just" some flames in the sawdust. Two lessons learned in one go!

End of digression.

[Andyjr1515]

As an absolute minimum you need something like this:

https://www.amazon.com/3M-Cartridge-Respirator-Assembly-07193/dp/B00079FOK0/ref=pd_sbs_201_1/261-4786373-5881552?_encoding=UTF8&pd_rd_i=B00079FOK0&pd_rd_r=7bf3280c-68f5-11e9-bbed-57e65051719f&pd_rd_w=EEGI7&pd_rd_wg=D3mbl&pf_rd_p=588939de-d3f8-42f1-a3d8-d556eae5797d&pf_rd_r=BD7V6G75WFN82837MHAD&psc=1&refRID=BD7V6G75WFN82837MHAD

They are not expensive but give you the P95 protection (95% protection against organic particulates) regarded as the minimum for paint spraying.  There are other makers around - the important thing is that the cartridges MUST be rated for organic fumes and vapours.

The other important thing is that they must fit properly.  A decent rule of thumb is that if you can smell the spray, you are in danger.

And yes - someone I know ended up in hospital for some considerable time spraying in his garage with the door open.

Also if you are thinking of setting up a booth, get proper advice from people who deal in such equipment, especially the electrical stuff.  Basically, yes, pretty much all powders and volatiles can create an explosive atmosphere.  There is a great case study of a custard powder factory that was FLATTENED...    Therefore electrical items like fan motors, etc, suitable for these kinds of environments are rated anti-explosion.  In Europe these electrical items have an ATEX rating (anti-explosion).  The US legislation may be different.  Again, generally not expensive but you do need someone who knows what they are talking about to advise or supply such stuff.. 

[mistermikev]

45 minutes ago, Andyjr1515 said:

As an absolute minimum you need something like this:

https://www.amazon.com/3M-Cartridge-Respirator-Assembly-07193/dp/B00079FOK0/ref=pd_sbs_201_1/261-4786373-5881552?_encoding=UTF8&pd_rd_i=B00079FOK0&pd_rd_r=7bf3280c-68f5-11e9-bbed-57e65051719f&pd_rd_w=EEGI7&pd_rd_wg=D3mbl&pf_rd_p=588939de-d3f8-42f1-a3d8-d556eae5797d&pf_rd_r=BD7V6G75WFN82837MHAD&psc=1&refRID=BD7V6G75WFN82837MHAD

They are not expensive but give you the P95 protection (95% protection against organic particulates) regarded as the minimum for paint spraying.  There are other makers around - the important thing is that the cartridges MUST be rated for organic fumes and vapours.

The other important thing is that they must fit properly.  A decent rule of thumb is that if you can smell the spray, you are in danger.

And yes - someone I know ended up in hospital for some considerable time spraying in his garage with the door open.

Also if you are thinking of setting up a booth, get proper advice from people who deal in such equipment, especially the electrical stuff.  Basically, yes, pretty much all powders and volatiles can create an explosive atmosphere.  There is a great case study of a custard powder factory that was FLATTENED...    Therefore electrical items like fan motors, etc, suitable for these kinds of environments are rated anti-explosion.  In Europe these electrical items have an ATEX rating (anti-explosion).  The US legislation may be different.  Again, generally not expensive but you do need someone who knows what they are talking about to advise or supply such stuff.. 

was just reading on tdpri that one should consider the 3M products as cartridges are readily available for them.  thanks for the direct recommendation.

afa went to the hospital?  please, tell me all you know about this scenario... what was sprayed, what sort of quantity, etc.

when I was young and worked at a cab shop... as a newbie there, I endured a lot of ribbing "tell V to go get the board stretcher" etc.  One of the worst things that they did to me, that was reckless and mean, was they asked me to go snag a wrench that was sitting in the bottom of a barrel.  I had never heard of acetone.  I breathed while I grabbed the wrench and it took me down.  Almost out cold.  Not cool.  Cabinetry exposed me to a lot of bad stuff... mdf dust, solid surface dust, chems for spraying sinks... never was told I needed a respirator until later on in my 'career'.  Even after all that, the noticeable damage from working in that industry is all in my knees and back.  Not suggesting at all that this is evidence one can ignore saftey precautions, just relating.

Not thinking of setting up a booth... but I am going to be buying a portable ac unit soon.  I'm guessing that is something I'd have to turn off if I was going to spray anything.  Can't imagine they make them with special fans.  Perhaps I need to consider a spray tent for outdoors... but there isn't much one can do to prevent health effects of 115 degree az summers.

[Andyjr1515]

It was nitro, spraying a guitar.  I'm not sure of the physiology, but my understanding is that nitro cellulose contains stuff that can be particularly harmful to your lungs.  My understanding is that he wasn't wearing any kind of mask and he just breathed in at the wrong time.

And that's the point of all this stuff.  What most of the H&S regs and equipment is trying to do is simply minimise the proportion of keeping safe that is just down to luck.  You don't HAVE to look when you cross the road, but you are less likely to be run over if you do look.  So yes, folks have been spraying in confined places without masks for decades - and many of them have been lucky.  I just don't fancy risking my well-being to the toss of a coin when a $17 mask will take away that risk.  I can pretty much guarantee that now, of course, me and my healthy lungs will be run down by a truck 

Don't get too hung up about the explosion stuff if you are spraying in a large well ventilated space.  The explosion risk is about critical concentrations of flammable fumes / dusts.  But if you start talking booths, then it is possible to inadvertently have those concentrations in localised areas.  So, for example, your light switches and peripherals in the room may be OK, but the motor for the fan taking the high concentrations out of the booth may need to be an anti-explosion rating.  All I'm saying is that if you start heading to enclosed booths, etc, do your homework.

[mistermikev]

6 hours ago, Andyjr1515 said:

It was nitro, spraying a guitar.  I'm not sure of the physiology, but my understanding is that nitro cellulose contains stuff that can be particularly harmful to your lungs.  My understanding is that he wasn't wearing any kind of mask and he just breathed in at the wrong time.

And that's the point of all this stuff.  What most of the H&S regs and equipment is trying to do is simply minimise the proportion of keeping safe that is just down to luck.  You don't HAVE to look when you cross the road, but you are less likely to be run over if you do look.  So yes, folks have been spraying in confined places without masks for decades - and many of them have been lucky.  I just don't fancy risking my well-being to the toss of a coin when a $17 mask will take away that risk.  I can pretty much guarantee that now, of course, me and my healthy lungs will be run down by a truck 

Don't get too hung up about the explosion stuff if you are spraying in a large well ventilated space.  The explosion risk is about critical concentrations of flammable fumes / dusts.  But if you start talking booths, then it is possible to inadvertently have those concentrations in localised areas.  So, for example, your light switches and peripherals in the room may be OK, but the motor for the fan taking the high concentrations out of the booth may need to be an anti-explosion rating.  All I'm saying is that if you start heading to enclosed booths, etc, do your homework.

cracked me up w the truck.  yeah, if only nitro was the worst thing my lungs endure (I vape... was a smoker... had heart attack... switched to vape... shouldn't really do anything... know I should quit and I'm stupid for it... I'm an addict... but on the bright side haven't had a drink in years!). 

all really useful comments.  particularly the $20 mask... I am going to order one immediately.  Have recently upped my dust mask to one of these rzmask carbon ones too.  on sale for $20 so... wouldn't make sense to not!

[ihocky2]

This is a little late, but minimum you need a respirator with activated charcoal filters. Still not as good as a fresh air system, but better than nothing. If you have a beard, fumes will still get in. At least put a coat of vaseline on the edge to create a better seal.

Nitro is flammable even once dry, but needs a source. Nitro cures by evaporation, so it does not generate it's own heat like linseed oil. But put a match to it and you'll see a nice flame. It's base component is used in gun powder to give an idea. 

[mistermikev]

On 5/7/2019 at 9:37 AM, ihocky2 said:

This is a little late, but minimum you need a respirator with activated charcoal filters. Still not as good as a fresh air system, but better than nothing. If you have a beard, fumes will still get in. At least put a coat of vaseline on the edge to create a better seal.

Nitro is flammable even once dry, but needs a source. Nitro cures by evaporation, so it does not generate it's own heat like linseed oil. But put a match to it and you'll see a nice flame. It's base component is used in gun powder to give an idea. 

i don't get notifications all the time so I missed your post... but wanted to say thanks for the advice!

[mistermikev]

On 4/27/2019 at 7:20 AM, Andyjr1515 said:

As an absolute minimum you need something like this:

https://www.amazon.com/3M-Cartridge-Respirator-Assembly-07193/dp/B00079FOK0/ref=pd_sbs_201_1/261-4786373-5881552?_encoding=UTF8&pd_rd_i=B00079FOK0&pd_rd_r=7bf3280c-68f5-11e9-bbed-57e65051719f&pd_rd_w=EEGI7&pd_rd_wg=D3mbl&pf_rd_p=588939de-d3f8-42f1-a3d8-d556eae5797d&pf_rd_r=BD7V6G75WFN82837MHAD&psc=1&refRID=BD7V6G75WFN82837MHAD

They are not expensive but give you the P95 protection (95% protection against organic particulates) regarded as the minimum for paint spraying.  There are other makers around - the important thing is that the cartridges MUST be rated for organic fumes and vapours.

The other important thing is that they must fit properly.  A decent rule of thumb is that if you can smell the spray, you are in danger.

And yes - someone I know ended up in hospital for some considerable time spraying in his garage with the door open.

Also if you are thinking of setting up a booth, get proper advice from people who deal in such equipment, especially the electrical stuff.  Basically, yes, pretty much all powders and volatiles can create an explosive atmosphere.  There is a great case study of a custard powder factory that was FLATTENED...    Therefore electrical items like fan motors, etc, suitable for these kinds of environments are rated anti-explosion.  In Europe these electrical items have an ATEX rating (anti-explosion).  The US legislation may be different.  Again, generally not expensive but you do need someone who knows what they are talking about to advise or supply such stuff.. 

BTW - just wanted to say thanks to you all for the info and support on this thread.  I bought the exact respirator above and it is working great.  nice to not have to take a breath, run in spray, run out and breath!  Should have bought that ages ago!  Thank you all again!  Can't promise it will improve my finishing skill tho!

[ADFinlayson]

Resurrecting a old thread here... I've just ordered myself a couple of cans of Nitro from https://www.manchesterguitartech.co.uk/nitrocellulose-lacquer/. I'm going to be refinishing a previous oil finished build. Ultimately, Crimson guitars finishing oil is not durable for a gigging instrument. I got it back recently and there are areas where his pick/finger nails have taken oil and stain away. I've done a few poly finishes now but want to give spraying nitro a go. 

Questions. How much lacquer should I be spraying on, how many coats? How long should I leave it between coats? As I understand it, if not enough time is left, the moister still in the previous coat will cause it to crack. I've got some cellulose sealer from another brand which I believe is compatible but I'm going to do a tester first. We seem to be in good weather in the UK currently so it seams like a good time to start this project.

[ScottR]

32 minutes ago, ADFinlayson said:

Questions. How much lacquer should I be spraying on, how many coats? How long should I leave it between coats? As I understand it, if not enough time is left, the moister still in the previous coat will cause it to crack. I've got some cellulose sealer from another brand which I believe is compatible but I'm going to do a tester first. We seem to be in good weather in the UK currently so it seams like a good time to start this project.

After spraying a couple of light dust coats, I generally spray 3 wet coats a day, with 15-20 minutes between them. Trapping solvents is not a problem between coats as those very solvents are what allow the coats to melt together into one. Trapping moisture will show up as blush, and that is not such a good thing, but there are remedies for it. Spraying too heavy a coat can trap solvent within that coat and create solvent pops--tiny bubbles that turn into pinhholes. These often show up in a run. Do not be afraid to spray too many coats.. They shrink and it is much easier to level a coat that is thicker than you want that one that is thin to begin with.

SR

[ADFinlayson]

23 minutes ago, ScottR said:

After spraying a couple of light dust coats, I generally spray 3 wet coats a day, with 15-20 minutes between them. Trapping solvents is not a problem between coats as those very solvents are what allow the coats to melt together into one. Trapping moisture will show up as blush, and that is not such a good thing, but there are remedies for it. Spraying too heavy a coat can trap solvent within that coat and create solvent pops--tiny bubbles that turn into pinhholes. These often show up in a run. Do not be afraid to spray too many coats.. They shrink and it is much easier to level a coat that is thicker than you want that one that is thin to begin with.

SR

Thanks man, so you say 3 coats per day, over how many days? how many coats are talking total? 

[mistermikev]

If I were gibson... I would sue you for hijacking my thread... how unoriginal!!!!!

I will tell you that my experience thus far with nitro has been nothing short of "why did I wait so long"!  for me... it is auto leveling itself.  There will be wet sanding to do... but I've been spraying it much heavier than normal... and even lumpy... and it ends up much smoother when it dries.  the downside is the 3 week wait to wet sand.  if you burn thru... that is a huge setback... so I've been putting on 1.4 cans worth just for a top.  I think I'm ready to start the 3 week wait just today... "must... not... attempt... to... wet... sand... must... be... patient... can't... hold... out... much... longer..."

[ScottR]

I do this over the course of a week, so say 15 -21 coats. Mind you, this is just my preference. There is no magic number. I like a thicker layer for ease of leveling and for the help it gives in pore filling. If you have a good non shrinking pore filler under the nitro you can easily go with less coats. Nitro does 90%V to 95% of its shrinking in the first 2 or 3 weeks of curing after spraying your last coat., but it keeps shrinking that last 5% for several more months. If you've got a solid job of pore filling under it that last 5% is no problem. If not, you are likely to see where the surface dipped slightly into the pores several month later. It will still be shiny as hell and those dimples will only be visible when viewed at just the right angle....but it's good to be aware of what happens.

And a final note on my preference for a thicker coat, I just love the added depth it gives to the figured wood underneath.

SR

[ScottR]

5 minutes ago, mistermikev said:

If I were gibson... I would sue you for hijacking my thread... how unoriginal!!!!!

I will tell you that my experience thus far with nitro has been nothing short of "why did I wait so long"!  for me... it is auto leveling itself.  There will be wet sanding to do... but I've been spraying it much heavier than normal... and even lumpy... and it ends up much smoother when it dries.  the downside is the 3 week wait to wet sand.  if you burn thru... that is a huge setback... so I've been putting on 1.4 cans worth just for a top.  I think I'm ready to start the 3 week wait just today... "must... not... attempt... to... wet... sand... must... be... patient... can't... hold... out... much... longer..."

I actually like to sand a grade or two after one week, a couple more after another week, and finish up after 3 weeks. In hot weather (something you get Mike, not so much for Ash) the surface can dry so fast that it traps the solvents underneath. Breaking the surface after a week helps any of those that may be trapped escape. (outgas).

SR

[mistermikev]

5 minutes ago, ScottR said:

I actually like to sand a grade or two after one week, a couple more after another week, and finish up after 3 weeks. In hot weather (something you get Mike, not so much for Ash) the surface can dry so fast that it traps the solvents underneath. Breaking the surface after a week helps any of those that may be trapped escape. (outgas).

SR

good to know.  I spose it's easier to get that initial level surface prior to full hardening too.  thank you sir!

[ScottR]

5 minutes ago, mistermikev said:

good to know.  I spose it's easier to get that initial level surface prior to full hardening too.  thank you sir!

It is a little easier, yes. I recommend leaving some small amount of leveling till after the third week though. There will be enough shrinkage into pores that you'll need to still level out at that point anyway. Might as well be sure you have enough nitro over them to allow for that.

SR

[mistermikev]

roger that... thanks for the schoolin'