Author Topic: Magic trick! Chamois and alcohol (Read 3305 times)

Larry Renger · « **on:** September 10, 2009, 08:53:32 AM »

I have recently stopped using conventional tack-rags and switched to using a piece of chamois and rubbing alcohol. The model comes perfectly clean with no possibility of fish-eyes due to the tack-rag wax. There is also no possibility of lint. It just works fantastic!

~>

Jim Kraft · « **Reply #1 on:** September 14, 2009, 11:46:08 AM »

Thanks for the tip Larry; Damp paper towels leave lint, and tack rags sometimes leave wax, or do not get the lint picked up. I have several small chamois to use for this. Thanks again.

Larry Renger · « **Reply #2 on:** November 30, 2009, 06:02:48 PM »

Anyone else actually try this? I have been using it regularly and had great success! You can wash the chamois after use to remove all old dust after use. It would probably work with other solvents such as Prep-sol, but I haven't tried that.

Robert McHam · « **Reply #3 on:** November 30, 2009, 09:56:49 PM »

Sounds interesting but I have to ask. Would this be a natural sheepskin chamois or one of the newer artificial chamois pads that are able to suck up 10 times its own weight in liquid?

Natural leather, from what I have learned over the years needs oil to keep it supple over time. Alcohol or prepsol will remove this much needed oil thus severely limiting the life of the expensive, natural, sheepskin leather chamois.
No need to concern oneself about this if the chamois is artificial.
The chamois's proper intended use is to absorb water from a painted surface thus eliminating water spots. Water will not take away from the oil and thus the chamois can be used for years, so long as it is dried properly afterward.

One thing that a chamois does not have is the stickiness that a conventional tac rag has that just grabs dust and won't let it go.
Cost wise, a tac rag is much less in cost per square foot can be reused without washing and simply thrown away later.
In addition there is no need to use (with additional cost) alcohol, Prep Sol or any other liquid.
A tac rag from Aircraft Spruce is only 85 cents. http://www.aircraftspruce.com/catalog/cspages/tacrags.php
A tac rag is specifically used for cleaning up the last remnants of dust just before applying paint.
For our small models, a tac rag can be reused thus making its value even greater.
There is no prep time involved with a tac rag. Open package, use. No need to soak it with a solvent.
If you intend to reuse a tac rag, simply return it to its package. No need to wait for hours to let it dry before you put it away.

Please keep in mind that I am not saying that this chamois/alcohol method won't work, it just sounds like a new (and far more costly) way to ruin a perfectly good chamois before its time.

I am now putting on my flame suit just in case.

Robert

Larry Renger · « **Reply #4 on:** November 30, 2009, 10:51:48 PM »

Good points, no flame here.

I build very few models a year, and use, pehaps 10% of a regular chamois sheet for this purpose. So far I have been able to do 3 models with a single piece of material. I think that the cost is minimal.

In some sort of volume production, it would be worth a better evaluation, but for my purposes, the total lack of wax and lint is the way to go!

Try it and like it or hate it, it is up to you! Don't try it and reject it, shame on you.

Russ Danneman · « **Reply #5 on:** December 01, 2009, 07:28:03 AM »

been using it lately.better than anything else i have done or tried. works excellent. russ

Peter Ferguson · « **Reply #6 on:** December 03, 2009, 08:52:39 PM »

I have no issue with the chamois but doesn't rubbing alcohol affect the adhesion of the dope. I used denatured alcohol to wipe down my airplane and I had major adhesion issues which I was told by members of this forum was due to the alcohol. I was instructed to use Naptha instead.

Mark Scarborough · « **Reply #7 on:** December 03, 2009, 10:04:07 PM »

FWIW,
if you are using a tack rag,, ( the official kind you buy for that purpose) and you get any material transfered to the surface, either you are working on a finish that isnt dry enough, or you are pressing to hard. A tack rag is to be used to remove lint, fuzz and particulate materials from the surface. any cleaning is to be done prior to that.
I am not a fan at all of using anything other than a tack rag for that purpose. I prefer water based wax and grease remover for actual cleaning prior to tacking. If you go back and review my post on the Avenger, you will see what can happen with alchohol on a finish. Yes it can cause major adhesion problems.

Bill Heher · « **Reply #8 on:** December 05, 2009, 08:45:00 AM »

I've often made my own tack rags from lint free wipes that I make "tacky" by spraying a fine mist of the paint/ dope to be applied at them from about 2-3 feet away. Let it dry for a few minutes and it will pick up dust etc. without leaving anything behind. Since the "tack" is the same as the finish to be applied there is no compatability issue.

The only problem is finding " lint free" wipes. I get mine from work, they are "Cleanrom Certified" and probably not generaly available in the usuall supply outlets. I will write down the info from a package and do a search to see where they are available, and what a suitable subsitute will be.

Balsa Butcher · « **Reply #9 on:** December 05, 2009, 10:08:33 AM »

As for cleaning solution - what is the current thinking on the old stand-by "Prep-sol"? FWIW: Last time I bought it in California it wasn't called that anymore - same product, same packaging, different name; "Tar Remover". Auto paint shop where I bought it said it was due to regulations, CA has fewer restrictions on this product if it used to remove tar than if it used as a paint preperation product...go figure.

billbyles · « **Reply #10 on:** December 05, 2009, 10:18:31 PM »

Quote from: Pete Cunha on December 05, 2009, 10:08:33 AM

As for cleaning solution - what is the current thinking on the old stand-by "Prep-sol"? FWIW: Last time I bought it in California it wasn't called that anymore - same product, same packaging, different name; "Tar Remover". Auto paint shop where I bought it said it was due to regulations, CA has fewer restrictions on this product if it used to remove tar than if it used as a paint preperation product...go figure.

Hi Pete,

The old DuPont Prepsol was a pretty good product for cleaning surfaces to be painted, however immediately after using the Prepsol you needed to follow up with a wipe of DuPont enamel thinner so it was pretty much a two-part cleaning. The new paint cleaning solvents are what Mark described above: water-based. I much prefer to use Sikkens M-600 paint cleaning solvent, no longer available here in California. However, Arizona (among other states) does still sell M-600, and it is the best paint surface cleaning product that I have ever used over the past 25 years.

I have found that denatured alcohol does remove some contaminants but not all. As long as the project that you are painting is new and relatively clean to begin with then denatured alcohol seems OK. Isopropyl alcohol contains quite a bit of water which may or may not be a problem depending how soon after cleaning you are going to paint. I just have not been favorably impressed with cleaning with the new water-based cleaners.

I also use tack rags as Mark stated above; getting good results depends on two things. First, get the correct tack rag for the product with which you will be painting. Tack rags designated for use with polyurethanes are less "sticky" than other tack rags and are less sensitive to pressure. They also work well with dope finishes. Secondly, do what Mark says and use very light pressure; a tack rag is not meant to be used with heavy (or really much at all) pressure against the surface to be painted. When I take a new tack rag out of the package I unfold it completely, then lightly "fluff" it into a kind of a ball, not compacting it at all. Then, very lightly rub it over the surface to be cleaned, with such light pressure that you don't even compress the "ball" of tack rag.

Then, I put the tack rag into a new or very clean round quart metal paint can and lightly set the lid on to keep dust and dirt out and to keep the tack rag from drying out. Taking care of the tack rag this way makes it possible to paint an entire airplane the size of the Boeing Stearman biplane using the same tack rag. While tack rags aren't very expensive I don't see any reason to be careless with them.

Balsa Butcher · « **Reply #11 on:** December 07, 2009, 12:00:27 PM »

Thanks for the reply Bill, I can't find Sikkens here in New Mexico either but...the search continues. As far as tack rags go, I've shied away from them because of perceived wax contamination issues but will try again using your technique. I have two stunters in (polar) grey primer so am following this thread with interest.

billbyles · « **Reply #12 on:** December 07, 2009, 02:50:09 PM »

Quote from: Pete Cunha on December 07, 2009, 12:00:27 PM

Thanks for the reply Bill, I can't find Sikkens here in New Mexico either but...the search continues. As far as tack rags go, I've shied away from them because of perceived wax contamination issues but will try again using your technique. I have two stunters in (polar) grey primer so am following this thread with interest.

Hi Pete,

As far as wax contamination from a tack rag goes, a few years ago I talked with a representative from a manufacturer of tack rags. He told me that the "tacky" element in a tack rag is not wax but is a non-drying varnish (or really, a very slow drying varnish - one that does not have dryers added). That is another good reason to keep a tack rag in a can with a lid when it is not being used...to keep the varnish from gradually becoming more dry.

I back up what Mark said about only having problems with tack rags when too much pressure is applied. I never just take one out of the plastic bag all folded up and use it that way. You will get much better coverage and dust pickup if you completely unfold it out to a single layer of the cheesecloth from which it is made, then "fluff" it into a ball and use it as described above.

Bill

Tim Wescott · « **Reply #13 on:** December 12, 2009, 08:21:25 PM »

Quote from: billbyles on December 05, 2009, 10:18:31 PM

Hi Pete,

Isopropyl alcohol contains quite a bit of water which may or may not be a problem depending how soon after cleaning you are going to paint.

FWIW Isopropyl alcohol can be had that is very close to dry -- popular concentrations are 70%, 90%, and 99%. Drug stores will always carry 70%, but never seem to have both 90% and 99%, so you have to check your area. I use 99% for cleaning and thinning epoxy, 70% and 90% for shrinking tissue (because the tissue only reacts to the water, not the alcohol; you get very good control that way). Sometimes I'll use the lower concentrations for cleaning if it's something that can stand ending up damp, and/or I can stand waiting for it to dry.

Note that you have to be aware that any sort of solvent cleaner doesn't make the contaminants go away -- it dilutes them. So you have to be careful that you aren't just thinning out a greasy spot and rubbing it all over the finish you're trying to clean. Use lots of solvent, and always try to do the dirtiest parts of the thing you're cleaning last, lest you just make the whole thing uniformly dirty.

Mark Scarborough · « **Reply #14 on:** December 12, 2009, 10:49:06 PM »

Well,
I reiterate, any time you experiment with something OTHER than what the MANUFACTURE of the paint product reccomends, it can and eventually will cause problems. I have been a painter for over 25 years. It still happens when you go away from the stated procedures,
you want to see what alcohol can do? look and read my thread on painting the Avenger,,

http://stunthanger.com/smf/index.php?topic=12573.0

billbyles · « **Reply #15 on:** December 14, 2009, 08:03:11 PM »

Quote from: Tim Wescott on December 12, 2009, 08:21:25 PM

<snip>

Note that you have to be aware that any sort of solvent cleaner doesn't make the contaminants go away -- it dilutes them. So you have to be careful that you aren't just thinning out a greasy spot and rubbing it all over the finish you're trying to clean. Use lots of solvent, and always try to do the dirtiest parts of the thing you're cleaning last, lest you just make the whole thing uniformly dirty.

The proper way to use a cleaning solvent to avoid the problem you describe above is to use two rags of new, clean, cotton tee shirt material. Soak one of the rags with the cleaning solvent to just short of dripping; use the other one dry. Wipe a reasonably small area, say the top of the outer wing panel with the solvent soaked rag getting the surface really wet; then immediately wipe it dry with the dry rag. If you only wipe the surface with the wet rag then you just float the contaminants until the solvent dries, then the contaminants go right back onto the surface. I have attended many of Sikkens painting schools and they are pretty definite about how to clean a surface to be painted...and this is possibly the most important step in painting.

You can also put the solvent in a pump spray bottle, spray it onto the surface, and use the dry rag to wipe it off, picking up the contaminants. Contamination can come from the most insidious places; one time I had a set of Beechcraft Staggerwing wing panels ready to roll into my spray booth and paint. My hangar doors were partially open and the guy two hangars upwind of me was spraying WD-40 on some parts outside. I had just finished cleaning the panels and immediately rolled them into the booth, turned the booth on and tack ragged the panels. As soon as I started spraying the panels it was apparent that I had a problem with contamination. When I went out of the booth I smelled the WD, looked outside and saw where the problem was coming from. Learn a lesson a day.

Since I was spraying two-part polyurethane on silver butyrate dope I was able to use the thinner for the polyurethane to wipe the paint off of the panels, then clean them properly and re-paint. It was kind of important to get the panels cleaned right away so that I could re-paint immediately and use the polyurethane that I had catalyzed. I was painting with a 5 gallon pressure pot so I had quite a bit of poly catalyzed and at about $300.00 per gallon I really hated to waste any.

Larry Renger · « **Reply #16 on:** December 15, 2009, 11:30:09 PM »

All this is very lovely, but I re-iterate: I have found plain rubbing alcohol and chamois to give me lint free, fish-eye free results EVERY time. Maybe it is not the ideal for a pro. I could care less. It works perfectly for me!!! Try it and reject it if it doesn't work for you. But if you don't try it, you have no reason to critique it!

Sure, if I were refinishing a full-scale aircraft for mucho bucks, I would go with the most proven system available (so I could bitch to the paint manufacturer if it fails, if nothing else). Liability would also be reduced that way. But this is a HOBBY and easy, simple methods are where we live.

Mark Scarborough · « **Reply #17 on:** December 15, 2009, 11:54:32 PM »

Larry,
more power to you man, I dont think anybody is telling YOU not to do your thing, my whole point is to share , based upon my experience, what I believe to be good and valid information to help other people from running into stumbling blocks. If it works for you, then more power to you like I say.

BUT, I have experimented enough to know, that I dont like to experiment when I have a proven, reccomended method, and based upon my experience, I will do things as reccomended by the guys that got paid millions to research it. for ME, and MY airplanes, the cost of a tack rag, is cheap insurance, just like the cost of a high quality spray gun, high quality thinner, and proper application. even with all the right stuff, things still go wrong, thats why I posted my experience ( see the link I posted) with using alchohol as a solvent. because I have had problems with it, and it cost me LOTs of hours to repair.
as I said, you do what you please, but dont get offended if everyone doesnt agree please. It works for you, great, I am not going to come into your shop and insist you do anything.
good luck and above all, have fun

Larry Renger · « **Reply #18 on:** December 16, 2009, 12:26:17 AM »

As if anyone could tell me not to do my own thing!

However, saying my technique doesn't work without trying it does not make sense! I agree that the pro techniques are reliable and sure. If you have a pro paint source available.

However, mine is available at the local supermarket and has been perfect for me. Use it or not, your choice.

billbyles · « **Reply #19 on:** December 17, 2009, 09:21:43 PM »

Quote from: Larry Renger on December 16, 2009, 12:26:17 AM

As if anyone could tell me not to do my own thing!

Who was telling you not to do your own thing or that your technique doesn't work, Larry? I have seen yours work up at Warren's and it works well. I was stating what works reliably on larger airplanes for me; techniques that have worked for years for me.

Larry Renger · « **Reply #20 on:** December 18, 2009, 10:19:22 AM »

Actully one guy did say it wouldn't work and would ruin the finish. Scan the thread and you will find it. (But I wouldn't waste my time on doing the search, myself).