I've Had it with Extira!

[mtworks]

I have tried for 4 months to get some consistant results with this material, with almost no luck.
attached is a photo of todays results. This is a simple porch sign painted with latex and Vcarved.
As you can see, as I pulled the mask off, the paint and primer both came up. This is happening 40% of the time with seemingly no rhyme or reason for it. i have tried many different primers with the same results- sometimes its good, and sometimes it does this! Does anybody have any good Ideas? - Details below-

Mask is avery 1828 paint- works well for me
paint is best grade exterior latex
prime one day, paint next, mask and cut third day
Primers I have tried:

Behr exterior latex and oil based primers
Zinsser oil based primer
Zinsser Shellac based primer
Zinsser Sealer and bond coat
Kilz oil based primer
Kilz2 water based primer
Amer. trad. oil based primer (current sign)
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[rookie432]

Wow Leo, I'd be pretty ticked off. I use extira pretty regularly and Sherman Williams paint by default(availability). I haven't had any major problems. I haven't used avary paint mask like you listed but by the looks of this I immediately think that the tack is too high.
I can sometimes get away with latex enamel paints from SW without the primer. I usually will use primer as a build up to fill and sand smooth. The only mask I have tried with carving is From All Star Adhesives and id cuts beatifully, my only problem with it is the tack isn't quite high enough.
For consistant results you may look at pre-coating with an epoxy. Hard coat the blank then sand and paint. Something like MAS Epoxies.
The sad truth is that there is not many equivalent options to extira without a pricetag. I like it because if there is a milling error than it's not a big deal like it would be with something like hdu.
Good luck

Bill

[joe]

Leo,

I wouldn't blame you for throwing in the towel. That's a really good looking sign gone bad. Like so many other sign guys, I've also had paint failure with extira.

If this were my sign I'd saw it up and mail it to the home office with a invoice. I'd also call and give them HELL! I think they have liability since they advertise to the sign trade.

Ok, all that said, I'm still using it on a regular basis. Like you, I've used lots of different primers with not much success. Some time ago I read, on the Letterville forum, about epoxy wash. With this technique I haven't had any paint adhesion problems. Two coats of epoxy, followed by Ronan block out white seems to work.

Why can some folks paint this stuff un-primed with latex paint and never have a problem? My best guess is Extira's water proofing solution is applied inconsistantly. I know for a fact some sheets are more oily

Extira has some mafor drawbacks. It's real heavy, the dust left behind is awful, and it's hard to get paint to stick to it. All this said, I'll probably keep using it anyway to make my fluted posts, and carving. I'd move away from it if I had another material to substitute.

I'd call em.

[joe]

Leo,

That's a very good looking sign and you deserve better than you're getting. I wouldn't blame you for throwing the towel.

Like so many other sign guys I've also had paint failure with extira. If this were my sign I'd saw it up and mail it to the home office with a invoice.

Ok, all that said, I'm still using it on a regular basis. Like you I've had with all the above primers. It seemed hopeless untill I was coached, on this forum, to use my famous epoxy wash. Two coats then a primer coat for the paint.

Why can some folks paint this stuff with latex and never have a problem? I think some panels are more heavely soaked with their water resistant compound. That's my best guess.

Extira has some real drawbacks. It's real heavy, the dust left behind is awful, and it's hard to get paint to stick to it. All this said, I'll probably keep using it anyway.

[billp]

I have previously posted my experiences, and reasons for not using Extira any longer. Joe has mentioned some of them above. The main (and ONLY ) attraction for most people is that it allegedly holds up better in the presence of moisture than other substrates.
BUT, it NEEDS to be primed and painted as it's natural appearance leaves a lot to be desired.
The only process that worked consistantly for me was two coats of 3lb. shellac. The alcohol base seemed to penetrate the surface better than any other primers. When I reported it to the Extira company (who I was doing the signs for) they thanked me and said they would "let all of their sales people know about this".....
If I had to use two coats of epoxy as my primer EVERY time I carved a sign, I'd just start with Trupan, and eliminate most of the hassles inherent in Extira.

[beacon14]

Just out of curiosity, what if any steps are you guys taking to prepare the surface before painting? I don't see any mention of sanding the surface before priming.

[donchapman]

Lots of folks complain about the high cost of HDU and then describe in great detail either (1) failures using substrates like Extira and MDF or (2) labor and time intensive methods such as epoxy washes to get Extira and MDF to work. That is false economy. I use HDU for almost all my exterior signs because it is fast, light and easy and has never failed me in over a decade of frequent use. On the suggestion of SignFoam I quit priming HDU several years ago and have never had an adhesion or other paint failure. At about $10/sq.ft in cost, 1.5" HDU is still a good value because of its dependability and labor savings, not to mention saving your back from having to lift Extira or MDF. My time is the major investment in my signs. Materials account for less than 25% of what I charge for a sign. The only sign failure I've had in 15 years was when I had a customer balk at the cost of doing a dimensional sign in HDU, so I did a painted MDO (not MDF) sign with vinyl lettering. I sanded primed and sealed all the vulnerable edges and put primer and 2 coats of paint on the faces. Two years later you could stick your finger through the rotten MDO because the customer let the lawn sprinklers soak the sign 3 times/week. I replaced the rotten sign with the HDU sign shown here. In the end the "economical" MDO sign cost more time, money, and worry than if I had used HDU the first time.

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[gerald_d]

Extira's guide for sign use

[joe]

Don,

I have to agree with you on HDU. I use it every day. It's another fine product. However there are also some headaches.

The first consideration. Screws and bolts don't work. Second, at legnth it's floppy. Third, finishing is much more deliclate than redwood or cedar. You've got to watch the edges. Weed eathers really get after it. This is probably the most deliclate sign material on the market in any weight lower than 18lb.

There's lots more condideration when using this material, but we can find ways to deal with them.

Finishing of HDU: Yes you can paint it un-primed, which works for some area's, but if you don't give it a good primer coat and sanding for those finishing area's it will look textured, unless youre using 18 lb. I prime it every time. I give a minimum of three coats of finished paint. Every sign looks better with three coats of paint and will last longer.

David,

Once you get a good adhesion coat you are ready to finish as usual. I use my orbital palm sander with P100. Give it a good sanding and proceed with a good primer.

Keep in mind the problem is getting a good, deep adhesion coat. Extira is made to repeal top coats of all kinds. I think that's the problem with this material.

Did I mention that HDU is gritttttey. I notice it most when my customer are in my shop, watching the routing process. They continually rub their hands together trying to get the grit off. It's everywhere. Much worse than fine sand. It's a love, hate thing.

[donchapman]

Here's what works for me in my lazy old age when I want to build and install my signs only once and have them last a decade or more.

I often use 1.5" 15# HDU and keep long pieces stiff enough with back cross supports of wood or metal as shown in the photos below.

All my HDU signs are mounted with screws or bolts and I've never had a fastener come loose.
But I don't live in tornado alley like you, Joe.

HDU is so light that course threaded fasteners will support it with no problem so long as they are not overtorqued and wallow out the HDU. I have many HDU signs hanging for years just by course threaded eye bolts screwed into predrilled HDU.

On larger heavier HDU hanging signs I drill oversized holes and fill with epoxy. I've sometimes made female threads by putting petroleum jelly coated bolts in the liquid epoxy and unscrewing them after the epoxy hardens.


I typically use many course thread hex-head sheet metal screws to mount HDU signs. Often I'll add silicone adhesive where the HDU makes contact with the support structure.
Using a cordless drill with a low torque setting it took less than 5 minutes to put 40 screws through predrilled holes in the wood and into the back of the wood support mounted HDU sign below without wallowing out any of them. The sign with the metal supports was similarly installed and has been up for about 6 years. Note that the paint is failing on the metal but not on the HDU. The metal was properly sanded, primed and painted with metal paint and still failed long before the unprimed HDU. If I need to remove the sign I can pop the silicone loose with a stiff putty knife.

I'd much rather deal with a little HDU dust than MDF dust or Extira oily gunk.

HDU dust is a very minor problem with my dust collector with door sweep foot. The exhaust air deflector on my PC router has helped cut down on dust too. The dust collector hose and ShopBot are well grounded, which cuts down on a lot of the static cling problem some folks have with HDU.

Primers were invented to provide good adhesion on wood, metal, etc and to build up a smoother surface. Paint adhesion is no problem with HDU so long as you let it dry between coats. An extra coat of high solids acrylic latex paint will build up a smooth surface as well as most primers. On HDU that's all that primer is anyway, a high solids paint of the wrong (usually white) color. Scratch the finish paint surface and you get to see bright white primer unless you go to the trouble of tinting your primer.

For HDU I use high solids 100% acrylic latex Porter paints without a primer coat almost exclusively and get as smooth a surface as I want or need depending on the number of coats I HVLP spray, brush, or roll.

I usually apply 3 or 4 coats and leave the paint in my spray rig cannister between coats with a wet rag over the spray nozzle. Easy and I don't have the added step of clean up and switching from primer to paint.

True, HDU can be easily damaged but few of my scores of HDU signs have ever been damaged and repairs have been easy. I'll sometimes protect particularly fine graphic or lettering details with a coat of epoxy, but I've never epoxy coated an entire sign like folks talk about having to do with MDO and Extira. What fun.

Landscapers are the worst threat and I avoid them by keeping vulnerable parts away from where weedeaters and lawnmowers are likely to be.

I still don't know how to keep Mockingbirds from pooping on my signs.


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