Nitrocellulose - request for advice

[plantagenon]

I am after a bit of advice on the use of nitrocellulose. I have done a couple of pens with it now and so far I am happy with the results. As long as they don't craze as someone mentioned might happen they will come out with a gloss as good as CA, albeit slower process.

I have attached a couple of photos to help explain my query. The first photo is a mallee burl that I turned and then dry sanded all the way up to 12000 with MM. I have done each of the blanks the same before the first dip.

The second and third photos show the results of the first dip into the nitro. On the third photo you will see a small ring of nitro round the bottom of the blank in the middle of the photo. My question is - If this ring remains and does not even out as it dries, is it possible to sand or polish it off after the nitro has cured?

The final photo is of the drying box I built. Instead of using metal bushes at the top and bottom of the blanks for dipping purposes I am trying delrin bushes and also the caps that come with the large tubes of silicone etc that I have cut down and which fit inside the blanks to seal them from the nitro dip.

Any advice on the final finish in terms of sanding and polishing would be appreciated. My previous efforts using metal bushes at each end will not require sanding as they dried perfectly and may just get a light touch up with Brasso as has been suggested previously.

[gawdelpus]

Not done any nitro finishes, but have some ready to try when time permits, I am almost certain that to avoid that buildup on the bottom you need to match the diam with your spacer to form a continuous line, as in your metal bushes ,that way the build up will be away from the end of the blank so no need to sand back . a bit of a pain to make all the sized plugs you need for the different kits,but only needed one end I think , probably a bit to do with surface tension as it flows around the sharp corner ,if it just dripped straight off that may not happen ,probably some highly technical reason for the effect,but we just want to avoid it hehe, cheers ~ John

[Sawdust Maker]

I agree with John

You need a bush at the bottom to stop that build up, something which follows the plane of the timber
interesting I hadn't thought about whether you actually need the selfsame bush at the top! hmm

Hey Mr Plantagenon
how do the tops look?

BTW I made the comment about crazing and it was with auto lacquer. I have no experience with nitrocellulose, so am watching with interest.

[edblysard]

http://i87.photobucket.com/albums/k143/edblysard/IMG_0852.jpg
Yes, using the original bushings top and bottom helps a lot.
Note the ring or puddle at the bottom of the bushing....as was noted, you have to have somewhere for the excess to run to...with the cones you are using, it can only puddle or ring on the blank.
Surface tension in the liquid, be it lacqure,poly or varnish, causes this.
I use the original metal bushings, and keep a jar of old lacqure thinner around, when the pen is finished and I am done with the bushings, I toss them in for a good soak.
I also keep the old, "worn out" bushings and use them just for the dipping.
Sanding nitrocellulose or acrylic lacqure even with the top # micromesh will still require a polish as a last step, so it is in the turners interest to make the dip process and finish as smooth as one can, often, sanding and polishing is ot needed.

[plantagenon]

Thanks for your advice. I hadn't counted on the nitro not running off the bottom of the pen without a bush in place. It is logical enough when you think about it. :doh: I have rectified the problem by ordering a second set of bushes so I can use one for dipping and the other for turning.

Unfortunately I will have to sand back the first coat I have put on the blanks but I will allow it to cure first before I hit it with sandpaper. In the heat we are experiencing in Brisbane at the moment it won't take long at all for it to cure.

Greg

[fubar]

First time posting in the pen section so be gentle please

Just a note of caution I hope that when you use the nitrocellulose lacquer that you are aware that it is quite toxic and have suitable safety precautions also will explode quite nicely if exposed to naked flame or hot enough heat source do not use heatgun air blower to speed up the drying process .

Hooroo

[Sawdust Maker]

Ed
That's a nice piece of wood

[plantagenon]

I have received some of the new bushes and changed the homemade ones for them and then dipped again. Its seems to be shaping up ok.

I was reading an article on nitro today and it spoke about it having a tendency to explode if exposed to any sort of spark, flame or very high temperature. Has anyone had any problem with it??

The other thing mentioned was that it yellows with age. I have the clear product and not the sanding version so do you think there will be problem with yellowing and if so how long does it take to kick in??

Also, the fumes as mentioned earlier may well be very toxic. I will have to wear a mask when applying it as it has the same effects on me as CA, although you are not standing over the nitro for as long. Maybe the Carbatec powered mask I have might do the trick??

I am happy with the nitro at the moment even though it is not as quick as CA to apply and dry. If all else fails it will be back to CA but I am hoping for the best.

[Big Shed]

Nitrocellulose based finishes are certainly flammable and contain a range of very strong, and volatile, solvents.

Not knowing which finish you are using, it is somewhat harder to comment on the yellowing aspect. If you are using a quality NC finish specifically formulated for the furniture industry then it shouldn't yellow unduly, certainly less than say a wipe on poly, but somewhat more than CA.

The best first step is always to request an MSDS (Material Safety Data Sheet) from the manufacturer of the product and perhaps give them a call and direct some of question to their technical people. They should know what the product contains and would be able to give you much more specific advice.

[fubar]

I have used on split cane fishing rods went yellow within 12months with exposure to sun but didnt crack and flexed very well also learnt the hard way not to speed up drying time:burnt::burnt::burnt::burnt::hbomb:

[plantagenon]

I bought it from SE Qld Woodworking Supplies who, I think, is a sponsor on here so I will contact them. It is more the fumes causing headaches that concerns me more than an explosion as I have had it for months without problems - sealed in tins and also mixed and sealed in a glass bottle. :fingerscrossed: :blowup:

Fubar - Was the fishing rod made from yellow cane?

[munruben]

I have used on split cane fishing rods went yellow within 12months with exposure to sun but didnt crack and flexed very well also learnt the hard way not to speed up drying time:burnt::burnt::burnt::burnt::hbomb:We live and we learn. :)

[BamBam53]

I found this thread, http://www.woodworkforums.com/f69/teflon-bushes-final-sanding-finishing-polishing-80767/, on bushes and have made a few sets from a 13mm thick cutting board.

Metal bushes are used for turning and then I switch to plastic for sanding and finishing. I dip finish with Cabot's Crystal Clear after putting the blanks and bushes onto a threaded rod.

I was getting a build up on one end of the blank like you do but have found that swapping the rod end for end a couple of times while the finish dries evens it out.

[Sawdust Maker]

Bam Bam

I notice the lable on your bottle says 50/50
what are you thinning it with?

how long have you been using it and what do you think of the durability

and yep it's not hard to make 'finishing bushes' with delron or even chopping board plastics

[Penpal]

In another life SWMBO in the 70,s owned a Photographic Studio, the Colour Lab I used figured photographing schoolies annually some form of protection on the pics would be an asset so I found a firm operating out of a factory in Marigold Street Revesby in Sydney who many years before developed this Laquer for the photo industry then onsold the idea to furniture makers. Well we used it for up to 500 pics sold the idea that even children spilling drinks on sprayed pics did not affect them simply damp cloth wipe. The firm sold it cut to High gloss down to matte.

We sprayed the pics on our back verandah leaving the laquer in a vibrator gun seldom cleaned, sounds weird but if the wind caught the pic simply wipe over with their thinners spray again. I bought 20 litres of it at a time I think it comes now in 4 litre tins. What I noticed was the frig shelving metal wire built up with the overspray up to 1/2 an inch always crystal clear.

Now a proffessional Turner uses this same laquer today in a large drum Sprayer that holds a real lot of laquer he too leaves the unit assembled the laquer dries as you watch almost. Now I am not saying use it no guarantees to anyone but I will pursue the material specs, same supplier still I know also of an Auto Body shop uses and distributes it in Canberra, anyway yet another way to go, never did see it go yellow. You can cut this laquer with their thinners by choice.:o

Kind regards Peter.:2tsup:

Another mate makes burl slices Pen Boxes to be amazed by uses this same spray leaves it in the gun. No names no pack drill. Product info to come.

[Penpal]

Just remembered sprayed from a can laquer semi matte finish, Brown Mallee.

Kind regards Peter.:2tsup:

[BamBam53]

Bam Bam

I notice the lable on your bottle says 50/50
what are you thinning it with?

how long have you been using it and what do you think of the durability

and yep it's not hard to make 'finishing bushes' with delron or even chopping board plastics

Hi Sawdust Maker,

I am using Crystal Clear Satin thinned 50/50 with water. Out of the can Crystal Clear is too thick and you get a very high film build. The 50/50 mix is touch dry in about 45 minutes. The blanks in the photo had two coats last night 60 minutes apart and a third coat this morning. Tonight when I get home they will go back on the mandrel for a clean up and polish.

As for durability, I have only used the Crystal Clear on pens for a few months and it is looking good on the pens I use daily. We have most of our wooden floors at home finished with Cabots Clear Floor, which is very similar to Crystal Clear. The oldest was done 14 years ago and is still looking good so it should be ok on pens.

One other great thing about Crystal Clear is it's water based and there is virtually no smell when you are using it.

Michael

[plantagenon]

Okay. Here are some photos of my first efforts with nitrocellulose laquer (pity it wasn't liqueur). They have been dipped 6 times and allowed a week to cure before assembly. I have not polished them. The first is a Sierra with some wood scraps I had left over from blanks. The second is a slimline with Esatern Red Cedar (borer holes free although the nitro filled them at 6 dips) and the third is a leather pen made by Jim and dipped by me to see how it would react.

[BamBam53]

You have got a good result with the lacquer, I especially like the leather pen.