View Full Version : Tempered Hardboard Prep for Acrylics: ISO STRAIGHT ANSWER!

02-18-2014, 02:52 PM
Hi Every-1,

I'm a newbie painter and I'm at the end of my rope over the tempered hardboard issue. I searched books, the web & art supply employees for guidance on prepping tempered hardboard for acrylic paintings only to find a raging debate on it's usefulness that, at times, seems akin to the Hatfield's and the McCoy's.

I am, in part, the architect of my own misery because I didn't do my homework (research) BEFORE purchasing a sheet of the stuff. I only skimmed the chapter in my painting guide covering alternative supports. Basically, I saw the words "hardboard" and "cheap" and ignored the rest. So I rushed to Home Depot and bought the only hardboard that Dennis the clerk told me they sell; tempered hardboard (4' x 8' x 3/16"). He even cut it into over a dozen pieces for free after I gave him a great, inexpensive, last minute Valentine's Day gift idea for his wife. :heart: I left the store feeling like I'd made the deal of the century.

That feeling was quickly replaced with buyer's remorse when I got home and began researching the subject of hardboard supports more thoroughly online. That's when I first learned about UN-tempered hardboard and how some feel that the tempered variety can ruin your work over time. But for every nay sayer, there was a proponent. In an attempt to err on the side of caution, I called Dennis the next morning and inquired about un-tempered hardboard. To my dismay, he said he'd never heard of it. That was the answer I got at Lowe's too. :(

Since the un-tempered wasn't readily available, I went back to the web to see if I could salvage what I already had. The methods of prepping tempered hardboard were just as varied. Then I found information on how to cover it with canvas but nobody seems to agree on the GLUE!!! ARRRGGHH !! :mad:

My brain is officially fried. So if anyone can tell me where I can get DEFINITIVE ANSWERS to the following questions, it would be a greatly appreciated.

Can I use the tempered hardboard I have or not? If I can, how do I prep it and with what products?

Is covering it with canvas a viable option? What are the products and processes for that?

Most importantly, which exact stores can the products & tools be purchased? Product brands would help too.

I have to admit, after the headaches I've dealt with so far, these hardboard pieces are starting to look like the perfect kindling for a BACKYARD BONFIRE to me right about now! Somebody please help me get some straight answers before I go looking for my lighter!! Lol


PS: Calm down environmentalists. I'm just kidding about the bonfire. :angel:

Charlie's Mum
02-18-2014, 03:24 PM
Go to our information kiosk, link in my signature, look for Classroom index, and then the classroom about Supports and their Preparation, by Einion. There's a section about hardboard.
Many people here use it. I have oil paintings done on it 50+ years ago which are still Ok and had nothing other than white primer on them.
Believe me, you haven't wasted your money!:)

02-18-2014, 04:01 PM
One way would be to find out the manufacturer of the hardboard you purchased (perhaps you can ask the service desk at your home improvement store who it is) then write to or call that specific manufacturer to see what their process is.

Also, I use Kilz or other super stain blocking primer before using gesso on top of a piece of hardboard. Read the label carefully to make sure you can use a water-based paint or gesso on top of it.

As for gluing canvas to hardboard, the only time I've tried it, I used the primer then PVA glue. I haven't had the piece long enough to evaluate how long it will hold up or anything so don't try it based solely on my experience plus I used oil paint as my medium and not acrylic.


02-18-2014, 04:18 PM
Several major manufacturers of art supports offer prepped hardboard panels, that's what I use most of the time. Many also offer linen and canvas panels made from hardboard. With that kind of support in the industry from respected brands in the industry I'm not worried about it.


02-18-2014, 04:26 PM
I've glued 8.0z raw denim duck (JoAnn Fabrics) to a 48"x24" hard board.
I used Elmer's Carpenter's Wood Glue because it's what I had on hand.
I've used that glue on some stressful and/or weighted woodwork.
In our case on a back support, it has no work to do but to hold the canvas. Brushed thin layer of glue on, put canvas on, rolled it with mamma's rolling pin, done. Gesso'd but not painted yet. Looks good, you'll be fine.

02-18-2014, 06:31 PM
I have been using tempered hardboard from Lowes and Homedepot for years, with no problems.
In the old days hardboard was tempered with oil and heat. I'm not sure what the process is now, but it does not contain an oily residue as in the old days.

I start by lightly sanding the side to be painted, then seal with Golden GAC 100. Next, I apply five coats of gesso, sand the final coat with fine sandpaper, and it is ready to paint.

BTW; I have found that if I add a little marble dust to my gesso, it provides a little more " bite " for the paint. Also I seal the back to prevent warping.

02-18-2014, 08:29 PM
My dad has painted on this material for over sixty years using white latex house paint as a base. The paintings look just as brilliant as the day he painted them.

02-19-2014, 01:40 PM
I use the stuff from Lowe's all the time. Hubby is a carpenter, so...
Only issue's I've had with it were created by my own two hands :angel:

07-31-2014, 01:58 AM
I went through the same research process you went through, and in the end came to understand that it was pretty much a WASTE OF TIME.

Hardboard manufacturing methods are far different than they were back when most of those warnings were issued. Actual Masonite hasn't been made for decades, and the current processes for either tempered or standard hardboard involve far fewer leachable impurities than they did before.

I know this thread of yours is pretty old now, so you've probably already resolved these issues. I just commented in your recent "canvas panel gesso" thread ("Go Commando") so maybe that's the direction in which you've turned... Either way, I'll bet you still have all or most of those Home Depot hardboard panels standing around.

My suggestion for how to put them to use:

Go back to Home Depot and buy a gallon of Zinsser GARDZ (http://www.rustoleum.com/product-catalog/consumer-brands/zinsser/primer-sealers/gardz-problem-surface-sealer). It's only about $23 per gallon (cheap!), comes in a regular paint bucket and cleans up with just soap and water.

It's a construction-grade "problem surface sealer" for walls that does an excellent job of sealing hardboard--no matter which kind you bought--against water, and that's your big concern when painting acrylics-on-panel. Give each panel at least two coats on EVERY surface: front, back, all four edges. You can just slop it on with any brush you like. It's very thin so it won't leave visible brush strokes. It goes on translucent white and dries pretty much clear.

Maybe I'm wrong, but it sounds like you're not equipped to make and attach 'cradling' to the back of your panels (cradling is the supporting wooden framework that [hopefully] keeps your panel from bowing). As a general rule, you can keep 'flat things' from bowing by doing to the back whatever you did to the front. This is especially important if you don't intend to cradle your hardboard panel. So if you applied 2 layers of GARDZ and 3 layers of gesso to the front of your panel, apply the same combination to the back.

Search WC based on my name 'Bothhands'. You'll find my thread(s) on this subject from back when I was researching and 'losing my mind' just like you.

PS. FWIW, I don't gesso the back of my panels, but I do glue cradling to the back. I attach the cradling, then paint all surfaces with GARDZ twice. Then I apply two light coats of gesso on the front only. So far, no problems, BUT...I'm pretty sure the cradling is helping me out. If no cradling, consider making front and rear treatments identical as described above.

07-31-2014, 01:15 PM
Have any of you ever used water based sealants like Bulls EyeŽ Water-Base Primer or Kilz?

07-31-2014, 01:58 PM
I have not.

I've used KILZ products in residential remodeling and typically have had good results. I'm pretty sure water-based KILZ would block any harmful leaching discolorations ("embarrassing stains" :D) emitting from your hardboard, but honestly, I don't think there's much to worry about in that regard if you're using recently manufactured hardboard. FWIW, I find the KILZ solvent-based primer to block stains a lot better than the water-based primer does.

A white KILZ stain-blocking primer might also serve as your "gesso". I think folks here report painting acrylics over standard Latex wall paints without problems, but there's so much emphasis on "proper" and "archival" materials and methods. I think galleries and/or patrons might turn their noses up if they find out you're painting atop KILZ and only KILZ. (Hey, that's the same stuff they used to hide the stains on my ugly bathroom walls! :D)

I suggest Zinsser GARDZ followed by a couple of light coats of gesso on the panel front only (and maybe no gesso at all). It's easy, cheap and effective.

08-01-2014, 09:51 AM
As long as I'm thinking of the right stuff...

Sand it down with some 220 grit sandpaper and prime it with gesso. That should be all you need to do.

08-01-2014, 09:53 AM
Thanks for responses!