Using Multiple CNC Passes to Get Clean Edge Detail When Routing HDU

When James Spouler with Mainland Woodworks got the job to update the signage at the Southlands Riding Club in Vancouver, BC, Canada, he used 15lb and 18lb Precision Board HDU to give the signs some depth and durability. Spouler also used multiple CNC router passes to get clean and deep lettering. Read on to see why he likes using Precision Board as a substrate for his dimensional signs.

James says the core branding design came to him from the clients branding designer.  “I took their vectors and made some adjustments to look good within the desired final sign dimensions using Vectric Aspire for my tool pathing software.”

He used PBLT-15 Precision Board HDU at 3″ thick for the larger main sign and PBLT-18 at 2″ thick for the second two signs.

Spouler prefers to use Precision Board HDU for outdoor signage, saying that “it’s thermally and dimensionally stable, essentially weatherproof, and UV stable.  It’s the best material I have found for painted exterior signage if you want it to last.”

For the deep lettering ( 0.8″ ) on the large main sign James first cut the lettering pass using a 5º tapered endmill.  “Then I cut the clear out passes in two depth passes leaving about 0.05″ and then one final finishing pass to remove that last 50 thousandths of an inch.”  He adds, “this lets me hog out the material fast and dirty then do a nice cleanup pass to get rid of any tear out or other blemishes that can be caused by weird or inefficient tool-pathing or by cutting too fast or too deep in one go.”

“I primed the signs with Coastal’s FSC-88 WB primer/filler, which took a little playing with to get used to, but once I thinned it to the right consistency, it worked great,” says Spouler (Ed note: Click HERE for tips from the experts on priming HDU with FSC-88 WB).

James painted the signs using the Matthews urethane paint color system saying, “it’s the best way I have found to accurately hit PMS colors at any amount you need to mix up, from a thimble to a gallon.”

Spouler says machining the Precision Board HDU took no time at all.  “Cutting the HDU goes fairly quickly, that’s one of my favorite parts of working with it.  It cuts fast and sharp and with a little planning you can really push the feed rates on it.”

Spouler uses a CNC machine which he built with his father-in-law.  “My father-in-law is an inventor and builder, electrician, plumber, and network systems engineer,” he tells us.  He adds, “the machine was originally based on open source MechMate plans, we built it with a 62″ x 122″ cutting area, initially it had about 6″ of Z travel, and of course, on the second project, which was planing a 5″ thick maple slab, we ran into the Z height limitation. and so we redesigned the Z axis with a lead screw and some linear bearings and rails to now allow for a full 16.5″ of travel.”

James uses a 2.2 kW water-cooled spindle on the machine and runs it using LinuxCNC.

Mainland Woodworks is a family run design and wood crafting team that is able to bring your ideas from a dream to a reality that you can see, touch and admire for years to come.  They offer a wide range of wood milling services as well as a large bed CNC router which can plane slabs and create elaborate 3D carvings.  You can call them at 778-241-6984 or visit their website.

Coastal Enterprises offers free samples of Precision Board HDU.  Already have a project in mind for our material?  Request a quote and get started today.  Sign up for our monthly blog roundup so you don’t miss any of our informative blogs.

Have a special project fabricated with Precision Board HDU and want to know if it could be featured in a blog on our website?  Give us a call at 800-845-0745 or drop us an email with details.  We’d love to hear from you!

UCSD Human-Powered Submarine Mold-Making

A team of engineering students from the University of California – San Diego (UCSD) designed and fabricated a unique human-powered submarine as part of their classroom learning experience.  Instead of using a rotary propeller, they took a cue from marine life and designed a dolphin fin propeller.  The students created fiberglass female molds out of Precision Board HDU which were used to create a carbon fiber hull for their submarine.  In a series of videos, the human-powered submarine team show us how they went from design to fabrication and every step in-between.


Tobin Gutermuth a structural engineering student and president of UC San Diego’s Human Powered Submarine Team and documented their process from design to fabrication and showed how they used Precision Board HDU to create female molds that would eventually be used to make a carbon fiber hull.  Competing in the one-person non-propellor division, Vaquita features an up-down tail for propulsion, a unique six-bar linkage, and the team’s very first pneumatics systems. The heart of the submarine is its drivetrain, which translates rotational motion into oscillation. The pilot propels the submarine by pedaling the drivetrain, which uses an innovative six-bar linkage to swing the tail up and down.

According to an article on the UCSD website:

The students made several major design and material changes to their sub this year. For starters, they’ve switched from trying to emulate the side-to-side motion of a tuna tail, and instead are mimicking the up-and-down sinusoidal movement of dolphins. The races in Maryland only require contestants to speed in a straight line, whereas the race in England has an obstacle component that the sideways motion wouldn’t be ideal for.

“We came up with a linkage system in the submarine tail to optimize for a perfect sinusoidal force output,” Gutermuth said. “Linkage systems tend to jump, but this one was optimized using a genetic algorithm to optimize for a perfect sweeping motion.”

“We used several 1.5 inch sheets of Precision Board to build 7 blocks of foam,” he says. They then machined the blocks of foam with a Kuka Robot CNC at UCSD to build a plug in seven sections.


Tobin says, “we bonded the sections together and made a fiberglass female mold from the plug.”  He adds, “we made an awesome carbon fiber hull in two sections using the female mold!”

You can see videos of the entire process below, including their test run in the pool.

The UCSD crew first cut the sheets of Precision Board into smaller size pieces to be able to bond them together.

They then took the smaller pieces and bonded them together into larger blocks using Coastal Enterprises PB Bond 240.

Then the UCSD team used a CNC machine the bonded blocks and assemble them to form their plug.

Finally, they shared with us a compilation video of the build process for Vaquita, their human powered submarine, showing all the mold making processes.

After the submarine was built, it was time to test it out in the pool.

After the submarine was completely built and tested, it was time to compete.  You can find out how they did at the 2018 European International Submarine Races in our follow up post with a report from the UCSD HPV team themselves next week!

The Human Powered Submarine team at the University of California San Diego designs and builds a fast, safe, and reliable fiberglass submarine that competes at international submarine races, which take place in Bethesda, Maryland and Gossport, UK. Scuba-certified students control the submerged and flooded submarine with human powered propulsion. Students working on this project learn essential CAD, machining, and programming skills and gain a deeper understanding of the concepts that they learn in their classes.  The most recent submarine, completed in 2018, is “Vaquita,” named for an endangered species of dolphin. Competing in the one-person non-propellor division, Vaquita featured an up-down tail for propulsion, a unique six-bar linkage, and the team’s very first pneumatics systems.

Coastal Enterprises manufactures Precision Board HDU, a high-density urethane material used extensively in the tooling industry.  It is a closed-cell rigid material that does not rot, warp or crack.

Coastal has a long tradition of donating Precision Board HDU to schools around the country in support of the next generation of engineers, designers and artists working in composites.  If you are interested in finding out more about our Precision Board school donation program, check out our School Donation page and get in touch with us to see how we can help your program out.

Creating an Architectural Gable with Precision Board HDU

When Shane Durnford created an architectural gable for a home, he used Precision Board HDU and hand-carved the incredible detail into it. For him it was a return to sign work & he couldn’t be happier about it. Shane talks about bringing this work of art to life through craftsmanship, skill and the use of Precision Board HDU.


Durnford was a sign writer in the 80s doing lettering and specialized in handcrafted signs. He taught himself how to carve in 1989 and it took on a life of its own from there.  Over the next 20 years Shane created thousands of premium carved and crafted signs for commercial, municipal and residential commissions.  After taking a break from carving and sign work, Shane recently had the opportunity to create an architectural gable from some PBLT-18 Precision Board HDU and jumped at the chance.

“This was my return to sign work and hand carving. It never left me. As soon as I picked up the tools, it came back to me,” Shane says. “It’s fun. I missed the craft.”

It took him about 100 hours altogether for the design and carving of the gable. He started with a flat piece that had the general shapes in it and then worked from there to carve dimension into the substrate.  “The 18 lb. Precision Board sheet was only about four inches thick, so I used shadow to give it a bigger look,” Shane says. “I start with a low point and high point for reference and then bring the picture into focus by shading with light and undercutting to give the substrate dimension,” he added.

Almost all of Shane’s work has birds in it. “They are poetically beautiful creatures.” he says.  “Almost everything I do is nature oriented and organic in shape and line. I think living in the beautiful countryside where I had my studio for years had a great influence on my work. It’s the place where my muses live.”

Because the bird’s wing on the right side of the gable was only about an inch thick, he drilled a ¼” brass rod through the bird and into the wing to give it strong support.  Durnford then used Benjamin Moore primer and latex paint with an eggshell finish.  He says, “I thought about painting the apples red, but it would visually clutter the sign and be a distraction to the entire architectural nature of the sign. More of a gable architectural feature instead of a sign.”

Pro Tip: “When carving, take it one section at a time. Pick your highest and lowest depths and establish those areas and then carve the remaining elements in relation to those two points. The detail comes at the very end, like a picture coming into focus.  Design and carve by feel and intuition and try not to over think the process. It’s like sketching. Rough it out and establish the over all composition, and then refine the detail. The learning curve is always steep and never ending. That’s what I love about it.”

Shane likes the feeling he gets when hand-carving high-density urethane.  “It’s a meditative and natural process. When I carve, I try to work intuitively. The carving pulls you inside the work and time passes effortlessly. You forget yourself and let the design find you.”

We asked him how he knows when a particular carving is finished.  “It depends on the piece. For exterior pieces I limited the detail, since it will be viewed at a distance. For more interior pieces the extra refinement adds to the intimacy and expression of the piece.”


Shane prefers to work with Precision Board HDU because there’s no grain or knots and has a nice consistent density.  He says, “no matter where you are on the material, it’s all the same consistency. It helps the carving, so you don’t have to adjust your work for the material.  I’ve used other sign materials and they don’t hold the edge like Precision Board does. The tools get along well with it.”   He adds, “I like the natural color too.  It’s a little thing, but it affects the mindset when carving.”

Durnford elaborates a bit more on his style.  “I approach the work as a designer rather than just a carver. The sign design criteria easily translates to interior architectural pieces like entranceways,  newel posts, mantels.  I think the key is to feel it when designing and carving. It makes for an authentic and honest piece that engages and connects with people.”

A great selling point for commercial signage.


Shane graduated from Toronto’s George Brown Signwriting program in 1981. With lettering quill in hand and a box of paint, he started from a humble shop in Creemore, Ontario and, within a few short years, had become a highly sought after Signcrafter. As a Registered Graphic Designer, Shane quickly became known for not only his superb hand crafting skills but also for his novel image consulting and design services, across various mediums: logos, websites, promotional/advertising material, illustration, corporate branding, and showpiece signage. His unique brand is sensory storytelling thru maximum impact, multifaceted visual imagery.

Shane’s work and articles have appeared in international trade publications. National exposure in major Canadian magazines and television. His work, as well as articles, are well respected within the industry. He has hosted design workshops, participants from as far away as Australia. He is retained as key note speaker for branding strategies by municipalities.  Shane Durnford Studios can be found on a variety of platforms, including his new Instagram account.  For more information and other social platforms, check out his website.  Design & Carving workshops are being organized for Summer 2018, more information to come. Email Shane to receive more info and pricing when it becomes available.

Coastal Enterprises offers free samples of Precision Board HDU.  You can also sign up for our monthly blog roundup, which is jam-packed with helpful blogs on people like Shane doing creative and interesting things with Precision Board.  You can also give us a call with your questions at 800-845-0745.  We’d love to hear from you!

Putting the Glass in Gramma’s Bloomers

When Kenna McCulluh wanted to make a sign for her side business, Gramma’s Bloomers, she decided to use the leftover Precision Board HDU pieces from larger projects at the full time sign company she owns, Custom Sign Center, LLC in Idaho.  She wanted to make a smaltz sign, but decided to crush her own glass from the local recycling center.  Kenna tells us how she made this mixed media sign from rescued material, much like her other designs for Gramma’s Bloomers.

glass smaltz

“I have a hard time tossing things in the garbage, so things that were once headed to the trash heap now ‘Bloom’ in to fun and unique items I list on my Gramma’s Bloomers Etsy store. I have fun mixing the drops with other materials like the recycled glass and sculpting epoxy.”

The Gramma’s Bloomers sign was made from a smaller piece of PBLT-15 and is 1.5″ thick and 11″ x 23″.  Kenna designed it in Corel Draw and then exported the eps file to Vectric V-Carve Pro and programmed the tooling for the sign.

She pocketed out 3/8″ deep where the glass was going to be, leaving the lettering outline and “bloomers” using her CAMaster Stinger 1 router. The flowers and letters were from the Precision Board HDU protective cover sheet that came with a larger order from her local distributor. She used a 1/16″ CNC router bit to tool the flowers because of the level of detail required.

precision board hdu

After routing the sign, Kenna primed it with two coats of FSC-88 WB everywhere except where the glass was going. Once the primer was dry, she added at least two coats of Modern Masters metallic paints.

“I love how Modern Masters paint feels when painting and how it picks up highlights and shadows,” she says.  For exterior use, Kenna says she uses Masterclear Protective Clear Topcoat to protect the paint. The flowers were domed with epoxy to give a little more height and effect.

“I’ve always loved the classic smalted signs and decided to pick up some recycled glass to try,” she says.  “It’s interesting because there may still be some paper left from the labels so it’s a process to clean it out but I also think it’s things like that which lend a certain personality to handmade items.”  Kenna gets her crushed recycled glass from the local glass recycling plant (Coeur d’Alene Glass Recycling Company).

She leaves the HDU un-primed where the glass will go so there is good adhesion between the HDU, epoxy and glass.  Kenna used West Systems Epoxy to secure the glass to the sign.  “I usually would use Smith’s Cream with glass smalts but I wanted to experiment to see how the epoxy holds up.”

Kenna made two of these signs… one for display and one to test out in the elements.  She says, “it’s better to experiment with my own things first. It helps me gain knowledge of the materials and techniques before I sell to my customers.”

Total project time?  Probably 10 – 12 hours total.  Kenna says, “I have to admit, I get lost keeping track of time on a project like this that is for myself. It’s more of an enjoyment thing for me rather than a job. Projects like these are great because you can do other things while primer, paint and epoxy dries, then come back and work a little bit more.”

Kenna prefers working with Precision Board HDU for many reasons. “The stability and endless uses for the product is amazing. It is also very nice to work with. The amount of detail you can achieve is far superior than with wood and you don’t have to worry about wood grain lifting or splintering while cutting or routing it. It finishes faster than wood as well.”  She adds, “In my opinion there is not a better sign substrate for dimensional signs.”

Kenna has been making the shift from mostly digital graphics to dimensional signage and finds that even in an “instant world where digital graphics dominate”, she can still find customers who are willing to invest time and money to get a unique and eye-catching sign.  “Quality dimensional signage is far from an instant product, however, there are many clients that are more than happy to wait and pay extra because they understand the appeal and value it brings to their image.” She adds, “it not only looks nicer than a printed sign but last so much longer. Besides, they are so much more fun to make and that makes for a happy signmaker!”

With 25 years in the sign industry, Custom Sign Center LLC knows the process from design and production to permits and installation.  Quality work, honesty, value and a passion for what they do combined with years of experience is evidence that you came to the right place.  You can give them a call at 208-664-7917 or visit their website.

Gramma’s Bloomers is a place where scrap items used in the sign industry and a mixture of other materials are lovingly transformed into new life. Items that were once headed to the trash heap now “Bloom” in to fun, imaginative and unique items inspired by the world around Kenna.  She believes it’s the little details that make each item unique so they become special to you. No two items are the same. Each creation was made so it blossomed with it’s own unique personality.  Gramma’s Bloomers can be found on Instagram and on her Etsy store.

Coastal Enterprises has a wealth of information on our website, from priming and coating Precision Board to the how our HDU cuts with CNCs, waterjets and lasersSign up for our monthly blog roundup and make sure you don’t miss any of our weekly blogs with tips and tricks from the industry on using Precision Board HDU!

Jumping the Shark: Hand-Carved Precision Board HDU

Are you wondering if Precision Board HDU can be hand-carved? Absolutely! We talked to Jim McKay who recently created a dimensional sign out of Precision Board PBLT-18 using only hand-carving tools and a dremel. Read on to see how he created the detail and depth on this 3D Mako Fin shark sign and get some tips on hand carving HDU.

Jim was asked to make a sign for the private shore house of a client who loved fishing. McKay decided to get creative with PBLT-18 that he had in stock. He did research on sharks and after finding the image he wanted, created a 3D outline in Adobe Illustrator, using it for reference as he hand-carved the HDU.

In order to create a sign that was 6″ thick, Jim stacked 3 pieces of 2″ foam together, drilled holes, inserted a wooden dowel and used PB Fast Set to hold the pieces in place.

McKay then used a high speed dremel for the detail work on the eye and teeth, using a variety of bits to achieve the dimensional look of the shark.

“To create depth from the front of the shark to the back, I started sculpting with rasps and a dremel to get down to the shape that I wanted.” He added, “from there I went back in with finer rasps and carving tools to get the exact details of where I wanted things.”

Once he was done carving, Jim put a base coat of primer/sealer on it and colored the shark with spray cans of grey and blue, silvery color paint. The eye itself was a piece of black stained glass to give an effect of a shiny pitch black pupil.

To give the illusion of the shark bursting out of the wall, he mounted it to a piece of exterior plywood and cut the edges to make it look like it was broken wood. He then put the finishing touches on the sign by hand painting his customer’s name on it.

For those thinking about trying their hand at carving Precision Board HDU, Jim has some advice.

“Since there are no knots or grain like in wood, HDU cuts real easy, so you need to be careful and not put too much pressure on it,” said McKay. “You want to try different tools on a sample piece to see how it carves. Take your time and do the work to quality finish with attention to detail, coloring, etc.”

Jim McKay is a trained illustrator who does a variety of work, including carved signs, painting and logo design. You can check out the Artwork by JTM website or contact him here to inquire about getting your own hand carved sign.

You can request samples of Precision Board to try for yourself and read more tips on working with HDU here.