Finishing Trupan & Extera

[joe]

Many sign artists continually dream of the perfect carving medium. Those of us who came up with a chisel & gouge could argue for hours as to which is better, Buttercut or Basswood. I still marvel over all the historical Oak carved furniture, but none of these last very well outside. Today we have synthetics that address exterior weathering and are router friendly.

When I started with Trupan I couldn't believe how nice it carved, light weight, sanded and hand carved well, cheap, lightweight, did I mention cheap, and just an allroud good sign product, but not an exterior product. We also use quiet a bit of HDU but it is expensive, and time consuming to finish.

Next we tried Extera but is was too heavy, and crude. Good for special products but heavy.

Back to Trupan: The weather proofing technique that seems to work best is as follows.

Two quick coats of shellac, burshed on. Not spray or rolled. Two coats of Expoxy or Fiberglass Resin.

While this leaves a beautiful dense product there is still the problem of through holes when attaching the sign to posts or building. I am sure some of you guys have a good solution for this. We are now drilling a 1/2" hole, tape off one side, and fill with epoxy, and tap a holw for bolt.

Would sure like to hear any test you guys have done.

Mark Fair is close to finishing my Web site. As a two person operation, I have strung this our for some time. Should be approx 75 more signs posted this coming week.

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

j

[Brady Watson]

Joe,
If I had to mount the panels on a facade, I would machine a pocket to conceal the bolt heads and then epoxy in a plug made to fit the hole...although your method may be the same amount of work.

I have been messing with trupan myself this week. I have a small run of relief carvings that I need to produce and thought trupan was an ideal candidate for the project...especially since it is much cheaper than wide-width mahogany and the fact that the woodgrain won't be seen anyway.

My main problem is dealing with the hairs after carving. I don't want to lose/wash out too much detail on the relief...but need a smooth surface finish. Do you think that the formula you supplied above will work?

-Brady

[jay]

Joe, just took a look at your new web site and the beautiful product you produce. Fantastic work, well done.

The signs that look like they have been sand blasted were they cut with a router or where they actually sand blasted?

[joe]

Brady & Jay

Thanks for your interest in my work.

Perhaps the relief carving should be sprayed. It is very hard to determine the amount of shellac deposited this way, but may be the best in this case.

I have attempted some small relief carving on Trupan but had trouble with the interior of letters smaller than 3/8". Second try was to paint a thin coat of shellac on the surface and route. Nope didn't solve the problem.

Are you doing 3D work, what bit, how deep, etc.

I must tell you: I disvocered a great product for letters, & detail work, it's untempered masonite. The stuff is just great to seal, sand, and finish. Did I mention Cheap? "Looks good and lasts a long time".

Thank you Jay for the complements. As I mentioned there should be a gob more photo's of my work next week. Mark Fair is preparing them for publication.

I haven't met Mark personally, he lives down south and I am in Oklahoma, but decided to hire him once I saw his web work.

Jay I do one of a deminsional sign from wood, HDU, and wood products. I doubt that you can tell the materials on the screen but would be pleased to tell you about any that you are interested.

If I could figure out how to post photo's on this forum it would be good.

About half of my time is taken up with design, bookwork, repairs, ordering materials and pesky phone calls. Few cold calls mature into a sale. The sweet, purple headed, little old lady, realtor has never purchased one of my signs. I'm hopefull.

I work fast and do most of it myself. This is not by choice, but I am too picky and kink of hard to please.

Thanks again
Happy Routing

j

[jay]

"The sweet, purple headed, little old lady, realtor has never purchased one of my signs. I'm hopefull."
That is why I stay away from retail!

I cut for a couple of the sign companies here . . . I do not compete with them, I want to cut for them. I hope that this way I will get to cut for all the sign shops here and no one will see the need to purchase a competing CNC router.

I should mention I will also cut for some of the designers as well but only after the designers come to me saying the sign people they talked to can't do what they want. The sign companies now know that if I quote a job for them I will not quote on the same style or design for the store designers. Shoot, I make more money cutting for the designers because I try to charge what the sign company would charge them.

[Brady Watson]

Joe,
I am using an 1/8" ballnose to cut to a max relief depth of 1/4"...however I need 1/2" of meat behind the carving for the overall structure I am making, so I either need 4/4 lumber or 3/4" sheet goods. I am at the borderline with Trupan at 18mm/.70". For the most part, I am able to sand some of the hairs off with a Scotchpad...but usung straight epoxy tends to raise the hairs and may fill too much of the relief.

I'll post if I find the miracle product/formula for this sort of thing.

-Brady

[billmaj]

Brady, Joe
I have experimented with many products to discourage hairs on MDF in general, and trupan. Franklin International, the glue company, makes a product called "Woodsise Concentrate" that very effectively seals these most porous materials. In fact, it is made for this exact purpose. It is a concentrate that you can mix to the consistency that you like, either for spraying or applying by hand. The advantage is that it readily accepts many finishes as a top coat. The disadvantage is that after application the item still needs to be sanded prior to the topcoat. It does sand well but depending on the amount of detail you are contending with, this could be tedious as I am sure you already know. Franklin is located in Ohio, phone # 614-443-0241. They shipped me a gallon for free so I could try it and were very helpful in helping me arrive at this product based on the my description of my needs.

The next best thing that I use is a vinyl sealer made by Sherwin Williams. This product does not seal quite as well as the Woodsise but does not raise the hairs as much (solvent based vs. latex, dries very fast and sands very well). I generally apply two heavy coats before sanding. You should probably have spray equipment to use this though. I like it better than shellac because it has a higher solids content.

Hopefully this helps,

Bill

[Brady Watson]

Thanks for the tips, Bill. I am probably going to be using Mahogany or Poplar for the carved pieces and Trupan for the flat areas. I need to make 7 CD racks for a local radio station. Since they are going to be finished in a black dye, species isn't too important. Trupan would be ideal if it didn't take so long to get those hairs knocked down...especially since it would widen my profit margin.

I just casted a chunk of USG's Rayite 100. I have to wait about an hour before I demold it. It is a gypsum based machinable media that can be used for temporary tooling. I believe Boeing uses it for short run parts. I'll post when I get something machined with it. Apparently it produces low/no dust, puts off a chip, and requires no coolant/lubricant. It can also be used with HSS bits.

We'll see how it goes...

-Brady

[joe]

Bill,

Thanks for the information about the Woodsise Concentrate. I'm sure it works very well. Is this a water based formula? Will give them a call Monday

The true test for us is the roof test. We coat out lots of wood products, date it, and throw it on our roof top. We check in on them ever so often to see how they are doing. There it get all the test necessary for our approval.

There are three reasons I use shellac. It is very fast drying, goes deep, and is a good base for Epoxy which does the real sealing.
It's not very expensive and available. This isn't any thing I think you guys are interested in, as our signs are exterior.

Do you guys have the chatter marks I do. Fuzz is second to the tooling marks. Yes I've tightened, lubed, till I've given in, and resort to sandpaper. Hair comes off fast with a little abrasive.

You talk about fuzz, Extera is King of the crop.

Brady,

Try masonite and when finished, use a stiff kitchen bruch to smooth it off.

j

[Brady Watson]

Joe,
You can get 3/4" masonite untempered, right? I have only seen it in 1/8 and 1/4. That would be the ticket if it is available and I can get a nice smooth finish on it.

I haven't experienced chatter marks, but aside from a profile pass to cut it out, most of my moves have been 3D. One thought was to 'shell' the machined areas with a liquid 2-part plastic and then go back and machine it again to get a hair-free surface. That is just not very efficient at this point, but a viable idea if you wanted to hard-shell foam let's say.

There is a product called Permalac that is supposed to be good over 10yrs outside. You can get it through Sculpt Nuveau if you can't find it. Very nice stuff with UV inhibitors, although not water based. SN has a water base clear now. Not sure durability though.

Here's a few shots of what I am working on in Trupan. The file took me forever and a day to make and get right within the limits of Rhino and MillWizard. You can see it will be a very visible item, so the finish has to be higher than that of an exterior product. So far, mahogany yields the best carved finish, although I haven't tried doing one in Poplar. Entire unit gets a quick mist of brown dye followed up with a black dye so all of the material will be concealed.

This is a CD rack for a member-supported radio station. It holds 25 CDs and resembles the steps going to their old studio.



5726
Conceptual Rendering


5727
Trupan carved 1/4" deep


5728
Trupan Isometric View

-Brady

[joe]

Brady,

You have a very professional piece and the quality of of the routing is top notch. You have done a great joy of design which will not show wear too easily.

I would choose Honduras Mahogony for the side pieces because I have had some bit scourching with poplar. I like poplar better for staining. I use analine die with clear shellac, them topcoat with min-wax poly for much of my work.

I am attempting to attach a couple of v carv thing. ArtCam Insignia is the program. These carvings are done in a short amount of time. Perhsps ten minutes or so.

j.
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5730

[Brady Watson]

Looks nice, Joe! I like the Collins piece a lot.

I have been using the Sculpt Nuvous dyes exclusively. They spray very well in my airbrush. I like them a lot since they don't raise the grain. After dying I just rub on some of the colored or clear SN wax. This eliminates the grain raising problem with water-based stuff, gives a smooth satin finish...AND I don't have to use anything that is too nasty fume-wise to finsh off the pieces.

If you haven't tried any of the SN products, I highly recommend them. Just about everything I do gets a SN product on it...wood or metal.

-Brady

[joe]

This image didn't make the previous message as it was too large. Made from Trupan and masonite. Masonite with 23K.
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[joe]

Painting Extira and getting the paint to stick is proving to be a challenge. I've spoken with several sign people in the past weeks about this, and we all have had the identical paint problem. I've ruined a 4'X14' carved panel, Lee Bently has tossed a carved 4'X6' carved panel, and Dale Kerr has failure on several finished pieces. Don't know what he plans to do. Perhaps he will let us know.

After contacting the manufacturer and getting their spec sheet, we have come to the conclusion they haven't done any in-houre testing with paint.

Here's one reason for paint failure. The top surface is rather fuzzy and it's necessary to deep seal with a hard coat, such as a clear polyeurthane, epoxy, sehllac, etc. This should give continuity to the flaky soft surface. Then you should be able to prime and paint as ususal.

In order to make Extira waterproof it's soaked in phenolic resin. While that makes it resists water, it also prevents water based primers from sticking. Oil based primers aren't much better and fail the making tape test miserably.

My post may seem severe, but we have a $3,200.00 sign to re-do. Probably should take legal action.

Will post later on the progress.

Good carving.

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

[beacon14]

The irony is that the manufacturer states that extira "must be primed and painted or finished before use" in order to validate the warranty.

Their suggestion: "Use a high quality exterior oil or alkyd solvent based or acrylic latex primer system specifically designed for use on wood composite products. Final top coat should be a high quality exterior grade paint system compatible with the primer being used. Consult your paint supplier or the paint manufacturer for specific recommendations" (from their web site)

Looks like they didn't do their homework.

[elcruisr]

Well, here's a different result. We did about 20 signs for a local RV park about 5 months ago with extira. They did the finish work and used an exterior latex primer from Ace Hardware followed by a low budget house paint. They have been out in the weather since then and with people talking about failures I went by to check on them. The paint is sticking good and no sign of failure on any of them.

Wonder if there's a production batch problem?

Eric

[Brady Watson]

Joe,
I like Zinser's White Pigmented Shellac. It will stick to just about ANYTHING and provide a good sealer/bond coat for you to add subsequent coats to. I use it to prime everything from wood to steel with excellent results. It is solvent based, but not nearly as nasty as laquer. Before I switched to Zinser I tested it on a piece of raw steel, unsanded and only wiped down with a rag. After 30 minutes I could not scratch it off with my fingernail no matter how hard I tried. Auto primer scratched off after 2hrs cure time. It is THE BEST primer to use if you can't afford to have paint checking and flaking off.

-Brady

[wendell]

I need a product like MDF but is waterproof.
I made yard signs for my school a few years ago and used MDO, a plywood product. We did way too much sanding.

IDEAS???

[joe]

David,

I think you may be on to something about the batch we received.

Dale K. and Lee Bentley also had failure with latex primer. No matter what success is posted about this product, we will move to the safe side and seal it off with something like Zinser or the like.

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

[paco]

Hi Joe (and all)!

Did you get to find the "right" way to primed Extira? ...and finish it?

I'm considering this product for my outdoor buisness sign but since priming and finishing seem problematic... not so sure...
I thought about using MDF too but I would need to seal it good since this will be an outdoor sign (though under a cornice so not supposed to get wet/damp)... I wonder if MDF could be sealed enought with a resin like polyester or epoxy...? Anybody did outdoor signs with MDF that last?

[fleinbach]

Paco

I don't know if this will help but I made a front porch out of MDF 5 years ago and it is still holding up well. It is mostly under cover but does still get lots of weather on the face. The front arch is a piece of MDF. You can see it here. http://www.homeimages.net/images/Pannella/Pannella%20Finished_0638.JPG

[paco]

Hey Frank!

Interesting!
How did you sealed/primed and finished it? What did you used?

[fleinbach]

I believe we used all water based paints. I'm not sure about the primer but the top coats where Behr exterior alkylide based.

[rookie432]

Paco and Frank,
I have a test piece of standard MDF carved and painted and mounted to the outside of the shop. Only a 12" overhang protects it. Primed and painted w/ exterior acrylics. 18 months and shows no sign of wear. I keep checking it expecting swelling or deterioration and keep getting surprised. Live in Ohio so it gets all the weather. My only guess is that the overhang on the shop provides enough protection to keep from deterioration.

Bill

[paco]

Thanks Bill and Franks!

I think I'll try it since it's cheap and available...