Corian Sign Questions for Keith or others?

Hello, I fell upon a piece of white corian that was an old countertop for an island in a kitchen. I have cut it down into manageable sizes with a skill saw and squared up some pieces on my table saw. I am ready to make some test signage.

I am planning on selecting a sign outline and lasering the outline on the corian and then cutting with a band saw (or scroll saw if it can cut it) and then sanding and routing the edges. I would then laser the sign using a paper mask and then spray paint over the masking.

I am wondering if this is the preferred method or if there is a better way such as using a template of the sign outline and cutting the corian with a router?

Can you use a keyhole router bit on corian on the back to make a slot for hanging the sign?

Also wonder how deep to engrave the corian when filling with spray paint?
Is corian suitable for oudoor signage?

Can you use something like rub n buff on corian? On a test piece I couldn't wipe the rub n buff off and had to sand it off?

I was at Johnson's Plastics last week in Minneapolis and purchased some of their Bond 634 Vinal cement. I am asuming this would work with corian?

Johnson's Plastics had some very nice looking signs made out of Romark reverse image material. You laser a mirror image on the back of the material and the front is a nice clear plastic matt finish. You can color fill different areas different colors and the signs looks very nice. Has anyone done the reverse imageing on regular acrylic? I tried but the matt look of the Romark seems to work much better? Don't know if there's a way to make acrylic more of a mat finish?

Sorry for all the questions but havn't worked much with plastics yet?
thanks in advance for any advise? Lynn

Lynn,

For what its worth here is my 2 cents on the topic of Corian and plastics for signage. In a nutshell I love using Corian and I can find most of my Corian stock for free from cabinet shops (sink-cutouts).

I am planning on selecting a sign outline and lasering the outline on the corian and then cutting with a band saw (or scroll saw if it can cut it) and then sanding and routing the edges. I would then laser the sign using a paper mask and then spray paint over the masking. I am wondering if this is the preferred method or if there is a better way such as using a template of the sign outline and cutting the corian with a router?

Your band saw will work nicely but you may find the scrollsaw to be very slow cutting Corian. Cutting your sign blank via pattern routing will work well but making a pattern is time-consuming and is normally used for mass producing signs of the saame design. One of a kind signs I normally cover the Corian with paper masking, then engrave the whole sign including the outline of the sign that is to be cut. After I apply the paint and it dries I remove the mask then cut the outside edge and sand with my spindle sander, finally use a router to apply the edge treatment.

You can make a pattern with your laser engraver to route your sign blanks from 1/4" acrylic if you are using a router guide, using a bearing will normally melt the acrylic.

Can you use a keyhole router bit on corian on the back to make a slot for hanging the sign?

A keyhole bit will in deed work on Corian, I use my drill press and a Grizzly G8750 compound sliding table to machine the hanger slots. This method is a bit easier and less risky than a router and pattern to cut the slots.

Also wonder how deep to engrave the corian when filling with spray paint?
Is corian suitable for oudoor signage?

Corian is a great material for exterior signage. Engraving depth isn't a major factor, you just need to make sure it is deep enough so the paint is sub-surface. I use a speed of 20% and 100% power with my 35 watt power supply. You can route the edges and then sand the top surface with your ROS then wash the plaque in cold water, the paint will not even be disturbed and will look great. I haven't tried polishing Corian after engraving and painting, that might be a procedure that would be best done before engraving.

Can you use something like rub n buff on corian? On a test piece I couldn't wipe the rub n buff off and had to sand it off?

Buffing Corian is a subject that we could discuss for a very long time. I have been working on a procedure for months and I have finally found something that works well. Obviously you start with sanding disks, 80, 120, 220, then move to Trisak disks then to buffing compound. It's not as bad as it sounds and if you want to go all the way to mirror finish you can do so or stop any time the finish suits you. Soon I will publish an article here at SMC with details of how I bring Corian to a mirror finish.

I was at Johnson's Plastics last week in Minneapolis and purchased some of their Bond 634 Vinal cement. I am asuming this would work with corian?

I can't be much help with this topic, Ken Dolph is one of the most knowledgeable people I know on the subject of adhesives for Corian. I have used the Dupont adhesive and CA Glue and Shoe Goo as well.

Johnson's Plastics had some very nice looking signs made out of Romark reverse image material. You laser a mirror image on the back of the material and the front is a nice clear plastic matt finish. You can color fill different areas different colors and the signs looks very nice. Has anyone done the reverse imageing on regular acrylic? I tried but the matt look of the Romark seems to work much better? Don't know if there's a way to make acrylic more of a mat finish?

I haven't used the product you mentioned but many of our members can probably help you with reverse engraving.

Sorry for all the questions but havn't worked much with plastics yet?
thanks in advance for any advise? Lynn[/QUOTE]

Plastics are very inexpensive and can be very usefull as an engraving material. You can mix plastic with wood and a host of other materials and get some stunning results and great signs.

Thanks for the info Keith, it is much appreciated. Lynn

Hiya , adding to Keith's post.

By far the best way to have your blank cut is to take it to a shop with a CnC overhead router , they can prolly accept your outline drawing and you then have a finished sign blank that corresponds to a laser template. Hand cutting or routing corian is fine too , tho is a lot of work to get nice edges and consistent shapes etc.
Corian works like wood mostly , so whatever works on wood tool wise , will most likely work on corian.
As to adhesives , well that depends on what you want to do , some more info would be great. However what we use to stick flat corian on backings or walls is marine silicon sealant (stuff used to glue glass of aquariums) , it sticks to the corain and whatever surface well.
Depth , as is said , enough to take a fill of wnatever you are filling with. We use water based acrylics as paints and often use pigmented resin as well. You can polish afterward using plastic polishes or buffing using tripoli bar. Buff polishing is the best , but you need various Tripolis (an abraisive buffing compound) and various mops on the buff and do it in stages , finally ending up with whats called a swansdown mop. Its messy and complex and you need powerful buffs etc. Hand sanding with a very fine waterpaper (wet) and then using a fine car paint cutting compound works quite well.
rub n buff and gilding pastes work well , be careful of metallics as they tend to deteriorate and dull over time in exposed environments.
I can give you a lot of advice on reverse etching/engraving.
The laser generally "frosts" the surface of the engraved section with these commercial reverse engraveable products and in fact some that are not expressly laser friendly dont work that well (the reverse stuff) Most do. You can make your own tho a lot cheaper. Basically you do get various thicknesses of acrylic (perspex) with various finishes (matt is called satinice - made by degussa). All you need do is pray these the colour you want as a background with spray paint and laser thru that in reverse.
There are a few things you have to keep in mind , there are 2 types of acrylic , cast and extruded. Cast works better for engraving "frosting " (cast is more expensive) and extruded works well for colour filling as it engraves clear. Lasers put huge stresses in acrylics and some plastics , so if you use solvent based paints after engraving , the material will and can stress crack. Prior to engraving , IE spraying , you can use solvents , after laser processing , only water based paints.
Using acrylic and reverse spraying/engraving gives you a huge amount of control regarding colours , thicknesses , surface finishes and the like. You can sandblast acrylic for a matt effect as well , but it marks easily on the matt surface with dirty fingers etc. you can also front engrave a light 1/2tone pattern on it for various "levles" of matt finish if you laser can handle shades of grey.

Corian comes sanded to at least 220 from the factory. Some is 320 and some is poured and not sanded. So I never sand less than 220 grit unless I am shaping. The fastest cutting liquid I have found is 3M Super Duty Rubbing Compound. I can polish from 400 grit to a medium polish directly. For finer polishung I use Novus products #3 and #2. It is important to use a hard flat block to back up the sandpaper if you want a very flat finish other wise you can get a microscopic orange peel finish.

Micro Finishing sheets work very well on Corian too.

If anyone is interested in the free booklet from duPont "Working With Corian in the Home Workshop", just e-mail me your address or call me at 1-800-724-4008. Do you know that you can heat and bend your signs after lasering? Makes for great effects.

Ihope this helps
Ken

Ken,

I have used my heat press to bend Corian and was wondering if you had ever used one of the heater elements that are normally used for bending acrylic to bend Corian. I expect that they might not be able to produce enough heat but it sure would be nice to be able to do 90 degree bends faster than waiting for the heat press to heat up the entire piece of Corian.

Rodne,

Can you provide a manufacturer and specific trade name for the marine silicon sealant?

Thanks for all the great info guys. I sanded some acrylic with 320 grit sandpaper on a random orbit sander tonight. It looks very much like the matt finish on the Romark Reverse image material. I am painting it now and will laser tomorrow.

When you talk about polishing corian with buffing compounds, are you doing this with a buffing wheel on a table top grinder or are you using an electric buffer similar to what would be used on an automobile?

thanks again Lynn

Keith,

It is always best to heat Corian completely through to 325 to 350 degrees F. Make sure that the oven is accurate. If you hit 360 degrees the ATH in the Corian will outgas steam. So the piece will end up looking like a relief map of China. It will also smell bad, very bad, but is not toxic.

Color is a consideration when bending. Microfractures can occur if Corian is bent too cool or too far. Darker colors will show microfractures as a white haze. Of course this will not appear to be a problem in the lighter colors. I have not tried a heat bar. I would suspect that it would take much much longer to heat Corian to bending than acrylic. Corian is 70 crushed mineral and that mineral absorbs a lot of heat per degree rise in temperature. Again 350 degrees is the highest you want to go.

Lynn,

Polishing with compounds: I use either a fixed buffing wheel (actually a drill press with a linnen wheel chucked up) or a wool bonnet on a buffer. If you rely too heavily on compounds you will get a pebble effect as different hardness of the material will abraid at different rates. Using a firm or hard block and sanding sheet will assure a smoother shinier surface. But the compounds can be very fast.

I hope this helps
Ken

Hi, there, I just added to Keith's post. I’d like to know the best way to laser engrave photographs in Corian. How do I have to prepare the material to color fill? Do I need to cover it with wax or something before engrave it? What’s the ideal color to get the sensation of gray? And finally, what’s the correct paint to use? <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>

Carlos,

I use PhotoGrav when engraving photographs on Corian. PhotoGrav does a good job of dithering which is important when engraving a material that isn't capable of the burning processes ability to provide shading. I haven't engraved but a couple photos on Corian, the results were very nice but not spectacular like black marble.

I use a paper mask to engrave Corian, engrave the photo then use a paint fill. I don't know what the best paint to use is, I have been using Rustoleum which seems to work fine.

Carlos,

I hate picking out the masking so I use one of the following methods:

1 ) Leave Corian unfinished and unmasked. Paint with any solvent based paint after engraving. I use "Odds and Ends Fast Dry Enamel" from Plasti-Kote. Quickly wipe it on a paper towel laid flat on the table. Allow to dry and sand and finish the Corian as desired. If you actually fill the engraving this will give you an inlaid look.

2) Finish the Corian as desired. Coat piece with a waterbased liquid masking. It is best to allow this to dry overnight. This is available at autopaint supply houses. 3M makes it but I have lost the label and cannot give you the number. Engrave it. Then you can spray or paint on your colorant. Allow it to dry. Wash off the masking with warm soapy water.

Both methods work well for me.

I hope this helps. Ken

Thanks for the info guys. I'll put it on practice and I tell you how I went.

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I agree with Ken; Corian, Avonite, Fountainhead..etal usually comes smooth. In my case I will run it up to 600 grit and it almost shines. I engrave without a mask (weeding sucks), colorfill with inexpensive colored car wax, and then wipe off after dried. Then hit it one last time at 1000 grit. Done! Trick is, have a couple 1/4 sheet sanders on hand with proper sanding grit. Also, scroll / bandsawing will eat the blades up FAST!! They have solid surface table saw blades and they do work great. I was doing a lot of resawing with solid surface material and inlaying the thin slabs after laser cutting. Got tired of buying bandsaw blades all the time. There are many possibilities and effects with this material tho'.

Just wanted to give you a tip for getting the pesky masking tape off the surface after engraving. After you color fill is completly dried take a credit card (plastic card) and push accross the surface at a 10-15 degree angle with the card. This cut the time it took to get the mask off by 75%!
Hope this helps,
Mike

Bruce V,

I resaw a fair amount of Corian. The Woodslicer blade from Highland Hardware works fine for me and I have replaced 1 blade in 12 years. The trick to keeping blades sharp is to cut slowly. When we slowed our feed rate from 120 inches per minute to 30 our blade life went up 11 times. Heat, not abrasion, is what kills blades.

Mike Wallis,

A fresh cut piece of Corian works even better. the edge is sharp enough to cut you. The material is more stable. Yet it stilll will not scratch.

Just a couple of thoughts
Ken