I recently brushed a liberal amount of some india ink in rubbing alcohol onto a light gray building and I wasn't happy with the results. I don't know the concentration of ink in the alcohol because I didn't make a note of how much I used. Of course it accumulated on horizontal surfaces like window ledges, but what I didn't like was the 'bathtub ring' that was left on some smooth vertical surfaces.
I'm using 70% rubbing alcohol and I wonder if the 30% water is puddling, the ink gathers at the edges of the puddle and dries like that creating a kind of 'bathtub ring'. I was able to remove the ink from the building by using window cleaner and a soft sponge. Before I try again, I want to buy a few bottles of rubbing alcohol and mix in measured amounts of ink - maybe - a quarter teaspoon, half teaspoon, teaspoon and tablespoon.
My question is - would using 90% alcohol prevent the formation of the bathtub ring? I'm thinking that if there is more alcohol and less water, the alcohol will evaporate before the bathtub ring can form. What do you think?
Thoughts, opinions appreciated, actual experience even more so,
Jeff
Quite possibly the "liberal amount" might have caused the problem. I'm really carefull when I used it on buildings, more so to bring out details, and I apply tiny amounts until I like what I see.
I've used "liberal amounts" on rock formations, but buildings, rolling stock, etc., I'm carefull.
But than again, I've only used the 90%, so, not sure if that alone would make any difference.
Mike.
My You Tube
I think your 'bathtub ring' is an artifact similar to paint 'runs' -- too much material applied for the surface to take. While the added meniscus depth due to water in the alcohol might influence the dimensions and darkness of the 'ring' that concentrated at its edge after the solvent dries, I think the real problem is putting enough on the surface to form the droplet meniscus in the first place. Keep doing the action of 'dry brushing' over the application area until there is only a thin film of liquid remaining.
Yes, if you don't have substrate-dissolving or paint-lifting issues with the 91% rubbing alcohol, use it. You could also try a tiny amount of a 'wetting agent' to keep blobbing to a minimum while brushing. (Can I mention Ever-Clear on a family-friendly forum? Sometimes ethyl alcohol works better than isopropyl ... )
jcopilotMy question is - would using 90% alcohol prevent the formation of the bathtub ring? I'm thinking that if there is more alcohol and less water, the alcohol will evaporate before the bathtub ring can form. What do you think?
The bathtub ring is where the wash dried before you added the next layer. It's important to keep the whole surface wet so there's no dry edge. This is true of any wash technique.
Of course this is tricky on large surfaces. Two ways to minimize the problem are to work quickly and to use a large brush.
Glad you were able to salvage the project with the window cleaner, I'll keep that in mind the next time I have a problem!
Eric
Regarding window cleaner . . .
In the old days when I was a young draftsman, we used actual ink pens. We filled them with India ink with a dropper from a bottle. We used ammonia to thin the ink. We had a ready supply of ammonia from the diazo blueprint machines. My point being . . . maybe ammonia (like in window cleaner) is better than alcohol to thin the ink for washes.
Robert
LINK to SNSR Blog
I keep three spray bottles with an alcohol/india ink mix ready.
One is for weathering and toning down ballasted track - 90% alcohol and a fairly large dose of the ink.
Another is for generic weathering on structures, roads, etc. There I have used 70% alchohol and less ink.
For rolling stock weathering I got 50% alcohol at WalMart and relatively little ink. Less alcohol because I do not want to remove any lettering or paint. When the model is wet with the alcohol/ink I make sure to let it sit as it would on the track, so that the weathering follows the same natural path as rainwater would when washing dirt down the sides and ends.
Following a tip -- can't recall if it was MR, the NMRA Magazine, or this Forum -- I have taken to highlighting edges, seams and creases on rolling stock, structures and vehicles with a very sharp #2 pencil before weathering, rather than relying on accumulated ink to do it for me. This is especially useful on vehicles which really need that slightly dark line around the doors, hood, trunk etc to avoid looking toylike.
Dave Nelson
One important thing to remember about the alcohol/India ink washes is to apply them before applying Dulcote. Otherwise it makes the Dulcote turn white.
Modeling the Pennsylvania Railroad in N Scale.
www.prr-nscale.blogspot.com
While I generally prefer paint washes to those of India ink, you can use a paper towel to wick-off excess amounts of wash when it begins to accumulate, rather than letting it dry. Either type of wash is cheap and easy to apply, so doing a second or third one, and monitoring it to get the effects you want may be a solution.
Wayne
Seems like my problem is due more to the amount of india ink in rubbing alcohol that I applied than to the type of alcohol. OK, thanks everyone, when I do this building again, I'll be more careful with the amount.
Eric, yes, I was surprised too when the ink came off so well with window cleaner. Before that, I tried just warm water and that didn't work so well. So,there was something valuable learned from this experience.
Dave, I did have the building sides standing when I applied the ink/alcohol which made the appearance of the bathtub ring even more mysterious. To have the ink accumulate on horizontal flat surfaces was expected, but the rings formed on perfectly flat, vertical surfaces, no edges to catch the ink. That, I didn't understand.
Thanks to everyone for your time and thoughts,
First off you need to use the right ink as there is permnent and non permanent inks. Always best to go with 90% if you can get it. All formulas should be measured or you will not be able to make more like in paints (too many varables).
Now for the overcoat part or flat clear coat. There is a slight difference between Dullcoat and Model Masters Lusterless Flat. You need to be a bit of a chemists to fiqure out the differances, which I am not but it seems to boil down to percentages of chemicals and the most important is one that affects the dry time. Always used the MM instead of Dullcoat after someone had issues and have never had any but since formulas change all the time, who knows.
doctorwayne While I generally prefer paint washes to those of India ink, you can use a paper towel to wick-off excess amounts of wash when it begins to accumulate, rather than letting it dry. Either type of wash is cheap and easy to apply, so doing a second or third one, and monitoring it to get the effects you want may be a solution. Wayne
I've never been able to get the hang of using india ink. I use very thinned paint.
- Douglas
jcopilot To have the ink accumulate on horizontal flat surfaces was expected, but the rings formed on perfectly flat, vertical surfaces, no edges to catch the ink. That, I didn't understand.
Ahhhh... did you carefully use detergent to clean residual parting agent, etc. off a plastic surface first? Hydrophobic surfaces will cause a water-based solution to 'ball up' instead of sheet properly.
I am tempted to see what a couple of drops of something like Jet-Dry in one of these solutions would do.
Someone advise me if there is supposed to be the analogue of a mordant in these ink washes. Does surface attack by the alcohol play a part?
I am new to the forum. It sounds like you wipe off the building or whatever after you let the ink dry? I am getting ready to build a light colored brick structure. After I use the wash, then I wipe off the dried excess, or wipe it while wet?
Thanks
Jamks,
While I have used India ink in rubbing alcolhol before, this was the first time I wasn't happy with the result. The majority opinion above seems to be that I just used too much. If you think you've used too much, the answer would be to draw off the excess using a corner of a paper towel, not to wipe the whole building.
In the future, I'll use an II/RA mix that is less concentrated (less India ink) and I'll apply it in smaller amounts, let it dry and add more if I think it's necessary.
One important lesson I learned - the India ink is removeable from a painted surface with window cleaner and rubbing with a soft sponge.
Hope this helps,