Masking Question

[fleinbach]

I need some advice before I go out and purchase some masking for which I will need to set up an account. It seems you need an account to purchase it from everyone who sells it localy.


I am making a special trim board using 5 1/2 inch Azek and there will be some design reliefs all the way down the board. I want to be able to paint the relief gold and the board will remain white. After searching the forum I came up with Gerber masking. They make Gerber I and Gerber II and I understand II has more holding power. My question is which one will work better to cut through? I've attached a picture so you can see the narrow pointed edges in the design. Will the weaker adhesive hold on the Azek? Or is there some other type I should consider.



5672

[Brady Watson]

Can't you just get the Avery mask from Harbor? It works really well and is a fraction of the cost of Gerber...

-B

[fleinbach]

Brady,

I just started with Gerber since it stuck in my mind for some reason but whatever will work is fine with me. So if Avery mask will do what i want that's fine with me. Are you talking ahout Harbor Freight or Harbor Sales?

[btk]

Frank,

I have used the Gerber II on Azek with great success. I have read about problems with Avery, however never tried.

Whatever you get, keep in a plastic bag as I think humidty can make it go bad prematurely.


Brian

[joe]

BTK,

Over the years there has been several types of masks used and tauted on this forum. For me all of the above mentioned masks are way too rigid for fine, deliclate carving of any surface other than glass smooth. Each has it's place however.

I've been using a very new approach that has worked out on both smooth and textured backgrounds. If you would care to give me a call I'd be pleased to assist.

Joe
(405) 366-1038
www.normansignco.com (http://www.normansignco.com)

[joe]

BTK should read Frank

Woops,

[Brady Watson]

Yeah Frank....Harbor Sales right in your neck of the woods.

-B

[jhicks]

Frank, the Avery Paint mask seems to have its ups and downs but I think its all about surface prep. If this were unfinished wood or mdf its Never going to happen because surfaces are just not smooth enough to adhere.
On the other hand we have used it effectively on painted PVC, painted medex, and even very smooth painted wood and hdu.
So I do believe it would work well on unpainted Azek iF you properly clean and burnish down in a very smooth manner so there are no air bubbles.
Of course once thats accomplished it will require a sharp bit and depending on the size of the very smallest areas to remain it does occasionally lift out and need some hand touched replacement before painting.
Now thats said, I know Joe has some cool new ideas Ive heard rumors about so definately get his new technique.

Mask here sells for about $35.00 for a 20" x 10 yard roll so test before the reeal thing.

[garyb]

As Jerry said Joe has some cool new ideas but they are not rumors, I was down at Joes shop last weekend whereby Joe showed us a new technique in masking that worked on smooth or rough finish material. His method gave nice sharp edges with no bleeding.
Joe is going to do a demo on this at the CNC Worksop here in a couple of weeks but I think hes working on a name for his new wonder product/process.......

[bpfohler]

I'm fairly new to sign making but I've been using Oracale 813 stencil film after reading some posts and it seems to be a great product.
I've cut the letters and seal them with a light coat of lacquer (something else I read here) and it seals the edges and prevents bleed through.

[jay_wyant]

Why not paint the carvings and sand the surface when dry? Azek is white all the way through, and this technique works fine on all of the v-carved signs I've done with pvc sheet stock.

[fleinbach]

Jay,

The surface of Azek is very smooth shiny so I figured if I sanded it it would be more likely to pick up dirt. I am making some tests after talking to Joe Crumley. I have not followed his specifications to the T as yet because I need an account to purchase one of the parts. But I have had some partial promising results. I also may try to get to Harbor sales to try some of the Avery mask Brady suggested. I just need to get some time.

[joe]

Jay,

It was good talking with you.

Since Azek has a nice hard smooth surface most any masking materials should work.

I'm interested in this product also. It may have lots of uses in the sign industry if it will hold up outside. There are so many new products coming on the market, it's hard to keep up.

Joe

[fleinbach]

Joe,
Adhesion

I have tried your method and it is about 90% affective but being that the AZEK is so smooth a surface the rubber cement pulls loose from all the narrow areas of the design. I also tried several other material combinations with the rubber cement but none worked so far.

Brady,

I finally got some time and purchased the Avery masking but it was no better than standard vinyl shelf material I tried. They both seem to be very ragged and pull completely off narrow areas. It is very easy to pull almost any adhesive off the surface of the AZEK and there doesn’t seem to be enough holding power on narrow surfaces. I was using a new 2 flute 1/4" ball nose bit at speeds from 3,000 up to 20,000 rpm but speed seemed to make no difference.

While making all these tests I have been racking my brain thinking about what would work as a masking on AZEK that would have enough holding power on the narrow areas and still be fairly easily removable. I finally came up with an answer and so far have made a hurried test that looks very promising. It worked 100% as a mask that cut very cleanly, but removal was not as easy as I had hoped for. I believe this may have been due to rushing the test and not allowing enough time for my releasing agent to work. I don't want to divulge what it is until I finish one more test to be sure it works easily. I will post my results either way hopefully by tomorrow.

It’s a good thing I have all these left over scrapes of AZEK to use for testing. If I had to purchase a piece just to do the tests I would have gone through about $100.00 worth already.

[btk]

Frank,

Once again, the Gerber II works great on the AZEK.
FYI, I got the Gerber II from these guys without account (they had drop shipped to me).
http://www.creativevisualsys.com

Brian

[fleinbach]

BTK

Are you saying you have actualy made cutouts on AZEK using Gerber II? And if so did you get clean cuts without frayed edges and did it hold up in very narrow areas. My problem so far has been mostly the area in the center of the flower that is pointed. Everything I tried held up in most places accept the points. But there was also lots of frying of the edges. Also if so what type bit and speeds worked for you.

[cnc_works]

I cannot venture an opinion about Gerber II on AZEK, but I have used it on many other materials and as long as I used a sharp bit, I got crisp edges with no fraying. Formica, melamine, painted MDF, painted fir, painted cedar, etc. I really don't think it possible to avoid the occasional small lifting - the internal sharp v of an A in some fonts for instance. Off course, your bit has to be able to cut the surface with no fraying or fuzzies, mask or not.

If you put it on bare wood, expect to pull chips, slivers and pieces up when removed, depending on grain and species of the wood.

I can tell you one instance I had a lot of problems. Put Gerber II down over a nitrocellulose lacquer surface that had not cured completely. The off gasses combined with and softened the mask adhesive which remained when I peeled the mask off. About three or four hours of no fun getting it off without damaging the surface or the engraving, I'll tell you!

Donn

[btk]

Frank,

I do not do a ton of sign work, however for the attached photos, I painted a sheet of AZEK black, applied Gerber II Mask and then Milled @ 1.7 in/sec.
For the V-Carved Sign, I used Amana 90 degree V Groove and for the other sign I used an Amana 2 flute (straight).

5673

5674

5675
The Straight bit did not have very sharp corners, however the V-Carve had narrow corners and also very fine lines and did not have any real problems. The only issue that I had was that in some sharp corners a "Hanging Chad" :-) would remain. I would just make a point to bend the chad back and make sure to keep out of the way of painting. The Straight carved areas of the top sign were not painted, however the V-Carved sign were letters were painted white.

On as side note: They say not to paint AZEK dark colors because of Expanision/UV, however I have been watching a sign I did that is installed accross the street from my shop here in NY (and the Ocean is just down the block) and have had absolutley no problems as of yet.

I also just yesterday did some signs that were carved into MDO using Gerber and had no tear out on the many sharp corners.

5676

Hope that helps.

Brian

[billp]

Here's a little taste of Joe's "secret sauce". More to follow when I get back home and download all the rest of the pix I took at the Kansas CNC Software Camp
5677

[denver]

I was trying masking on a practice project, and had similar problems as Frank: mostly ok except for the small areas and sharp points, but also somewhat fuzzy edges in places.

Based on this discussion, I now believe that most of my problem was probably just due to the surface not being perfectly smooth. And that makes sense. However, somewhere I read about two other possibilities:

1. Make a first pass just deep enough to cut through the mask.
2. Make sure your spindle is exactly perpendicular to the table, or it can cause fuzzy edges in spots.

Any comments on those?

Thanks,

Denver

[phil_o]

When I was in high school, about 40 years ago, I worked for a small cabinet shop. They made display cases. The exterior of the cabinet was a wood grain melamine type product and the interior was painted plywood. One of my jobs was to paint on a white latex mask material on the melamine so that the interior could be spray painted. The material peeled off easily after spray painting. I haven't seen a similar mask material since. Is anyone familiar with such a product? I wonder if it would be suitable for CNC purposes.

[joe]

Phil,

Good to see your post.

Like you, I've been on a quest for a good mask also. The vinyl masks are too rigid to be affectively on textured boards such as rough cedar and easily lift, leaving paint bleeds. They are just awful on anything but smooth surfaces.

I'm in the developmental stages for a mask and Spraylat seems like a good option. The criteria would be to paint on the mask, shear smoothly with a router bit without lifing, and easy removal.

Perhaps the material you were using as a kid was Spraylat. It's still in use and can be purchased by the gallon at most sign supplys. It's a latex and very safe to use. www.spraylat.com (http://www.spraylat.com)

I think it will meet the above criteria with the only question of easy removal. Lets keep on the trail to find a solution

Joe
www.normansignco.com (http://www.normansignco.com)

[btk]

Joe,

On some construction projects, I have used this stuff that brushes on to bathtubs, etc for protection from scratches and then peels off without leaving any residue.

http://www.pro-tect.com/catalog/index.php/cPath/22_42

I am not sure how it would work for sign carving, however the stuff really worked great.

Brian

[joe]

BTK,

Thanks for the tip.

It looks as though Product Protec 11 would be worth a test. The price is right too.

Has anyone tried this product for masking?

I'll give it a go and post the results.

Joe
www.normansignco.com (http://www.normansignco.com)

[btk]

Joe,

Actually, I am sure it is the same product, however the one I used I purchased here...
http://www.protectiveproducts.com/scratch.html

Brian

[fleinbach]

Well I didn't get enough time to finish my test as I was rushing all day yesterday to get parts cut for a theater room we are installing this week. But I see a lot of you are coming up with some possible solution without reinventing the horse.

When Phil mentioned the latex mask I did a search on the net and came up with a company that carries several varieties for different applications. I sent them an email to see if they have something that will work on the AZEK.

http://www.strippablecoating.peachhost.com/Home.htm

It seems to me one of these companies has something that will work. I am sure there has to be some masking material that will not only be easily appied then cleanly machined and still be easily removed.

[fleinbach]

Ok,I finaly found time to post my progress with this problem. In between jobs I did some more tests and my results have had good and bad points to each. First I will start by saying my earlier test machining AZEK with a 90Deg V bit produced lots of areas with fragments that where very time consuming to remove. This was with a brand new V bit and I tried everything from 3,000 RPM to 22,000 RPM and move speeds from 1 ips to 8 ips. The cut quality was nearly the same at all speeds. I found that if I switched from a V bit to a ball nose I got much cleaner cuts with almost no fragments to clean up.

Now I was at that point when moved on to the next step that of masking so I could paint the cutouts. That’s when I ran into my next problem and started this thread.

Brady said to use Avery mask so I tried it and when cut the masking was very ragged everywhere.

BTK said he uses Gerber 2 on AZEK and it works fine. That's when a fellow Shopboter near me called and said he had some Gerber 2 and I could try it out. So last Sunday he brought it out and we tried a cut which turned out no better than with the Avery. When he saw the way it was cutting he said he did not have this problem when he made his cuts with a V bit. So we put in a V bit and now the masking cut cleanly. But the V bit still left all the fragments in the AZEK again.

So I have come up with the following conclusion. The ball nose bit makes a nice clean relief cut that requires almost no cleanup but tears up the masking horribly. The V bit cuts the masking very cleanly but leaves lots of fragmentation of the AZEK to clean up. I must say though that the V bit makes a bit nicer looking relief.

Now I will describe my alternate test method of masking which does work very well even with a ball nose bit but takes more time.

I wanted something that would hopefully have 4 characteristics
1. Be easily applied.
2. Machine cleanly.
3. Hold fast in narrow areas.
4. Be easily removable
My solution has all the above plus a bonus, it is most likely the cheapest material you can buy. About the only downside is the wait time between processes. My material is All Purpose Joint Compound. I was racking my brain when I remembered how well this stuff adheres, yet how easily it is removed. When we are doing remodels and the drywall mud drops on floors, carpets counter tops etc. customers tend to think it is the end of the world. I always have to reassure them this stuff cleans up completely with plain ordinary water. I can think of nothing else that cleans up any easier.
Here is the steps I used:

1.

[jhicks]

Interesting Frank, I'm surprised it will stick to PVC but it sounds like a simple solution. Nice work.
I imagine Joes rubber cement would dry faster and adhere and peel away but whatever works is the way to go.

[fleinbach]

Jerry,

I'm sure Joe's rubber cement works on other materials but it did not work on the Azek. The bit would peal it off in some places leaving about an eighth of an inch exposed. It just doesn’t adhere to the Azek that well.

[joe]

Frank,

Thanks for the update. I'm just itchen to get my hands on that stuff. BTK's work is so neat and he's getting on well with Gerber.

When I get some, the first test after a good cleaning with alchohol, is strait rubber cement with no paper mask on top. The only reason for the paper mask is to assist with removal of the RC. The mask is the RC itself and it's so fleable I would think it wouldn't fly off.

My masking test with Gerber and Averys on textured surfaces failed for two reasons. First the masks didn't conform to the texture. Not only would it fly off on tight detail, it failed when paint would seep under the edges.

Thanks again for posting.

[fleinbach]

Joe,

I did the rubber cement test without the paper on it and that's when it pulled off near the edges. Rubber cement comes off this stuff real easy. In fact after it drys all you need to do is run your finger lightly across the surface and it comes right off. It does not adhere to AZEK well at all. Now it may have worked with the paper on top if I had used a V bit to make the cut but a ball nose bit just tears the paper the same as it tears the Gerber and Avery masking.

[procarve]

anyone ever try any of the commercial paintable maskings yet? results?

[joe]

Bill,

The search will continue for a long time since there doesn’t seem to be single material which will do a good job on all surfaces.

The general rule goes something like this.

Smooth, non porous surfaces are suitable for vinyl masking products. Textured surfaces, such as rough cedar, need a liquid mask. I’ve used several commercial masks and fall back on rubber cement. Another mask I've tried is Spray Lat. This is a water based maskant.It’s been used in the commercial sign industry for years and does a nice job on some, not too textured materials, but can be a real pain to remove.

Plain old rubber cement can be effective when used in conjunction with Transfer Tape. The tape has a rubber cement adhesive, and it removes the cement in a clean sweep. Keep in mind, the tape is only used to remove the cement. It's not really part of the masking process. I’m sure there are other solutions which will do a good job, but removal is one of the concerns.

I look forward to hearing of any other processes. It’s lonesome out here pushing the masking front.

[john_l]

Joe, Where would we get rubber cement in larger cans? Do you just brush it on with a disposable or chip brush of some sort?

[joe]

John,

You can purchase rubber cement in pint cans, $7.00 at Office Max or most any office supply.

Applicationis is simple. Just pour enough on your panel to cover the desired area. Be generious with it. Use a small vinyl application squeege or stiff cardboard about 4" wide. Leave plenty on the surface. Should be dry enough in an hour to apply transfer tape.

I'd burnish the tape down with a rivit bursh or hard squeege. It's not very critical since the the tape is only used for rubber removal.

Good luck

[ckurak]

Joe,

Let's see if I have this correct. You apply the tape BEFORE carving?

Thanks,

Charles

[joe]

Charles,

Yes, The problem with tape application after carving would be the amount of dust the rubber cement would collect. Preventing it from being as affective.

Please post your results.