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MDF s a great product to use if you want to really have some upset customers! It soaks up water like a sponge (even though it isn't suppose to)and crumbles like particle board.
------------------ Greg Gulliford aka MetroDude Metro Signs and Banners 1403 N. Greene St. #1 Spokane, WA 99202 509-536-9452
Greg's right about the MDF. A far better product for outdoor work is called MDO. (Medium Density Overlay...,I think).
You primer and seal the edges with a good oil based primer, then apply a coat or two of oil based enamel. The resulting sign should last a good long time.
MDF: Interior display use, interior carved signage, interior display use where durability is an issue (museums, schools, other institutional settings), solid substructure for other sign elements. NOT FOR - Structural integrity. NOT RECOMMENDED FOR - exterior application, sandblasting.
HDU: Interior or exterior signage - sandblasted, carved, or routered in nature. Can be a replacement substrate for MDO or other wood based substrata. NOT FOR – Structural integrity.
My short list… HDU is lighter, per square foot, to MDF HDU is available in differing densities, per cubic foot; I don’t believe MDF is. HDU is completely waterproof, most MDF is not. HDU is mold and mildew resistant. HDU is easier on carving and cutting tools. HDU, in some opinions, does not offer a good “feel” when hand carving, compared to MDF. MDF has a smooth finish in raw form, HDU does not. MDF is solid and can withstand a greater impact than HDU. MDF is lower priced than HDU. MDF, due to lower cost, is often used for verifying tools paths on CNC machinery. HDU, in our industry, has a greater perceived value. HDU, in raw form, becomes “surface brittle” when exposed to UV light. HDU, generally, can be machined more aggressive than MDF. MDF can easily warp/sag if not properly stored. HDU is easy to repair compared to MDF. (If even possible for some MDF cases)
Glenn, As stated in the other post, call locale distributors for product samples, request literature, and ask for references of other shops using the materials. Contact those shops you feel comfortable with and ask for both positive and negative feedback. Read the manufactures web sites for information; call and request answers to any remaining questions. And if you go to any trade shows, give personal feedback to the distributors and manufactures.
Gather as much info as possible, experiment with the product, and then form your own conclusion. Many here, myself included, frown on MDF for exterior applications. However there is a hand carver within 50 miles of me that uses that material almost exclusively for very high-end entrance signs to large estates. It’s comes down to what you feel comfortable with; comfortable working with, comfortable standing behind, and comfortable profiting from. Wished profitability no matter what substrate!
MDF is available in WR grade (water resistant) but as stated above is probably only really suitable for indoor work. Proprietary names used here for MDF are Customwood & Craftwood as well as a couple of others. Chances are if you look around your house you'll find a few things made from it, furniture, bathroom vanities, kitchen cabinets etc. You can buy it in sheets coated with melamine which make a good substrate for indoor work. Melamine edging can be bought at the hardware and applied with an iron and trimmed with a file. Thicknesses available are 3mm (3/16"?), 6mm (1/4"), 12mm (1/2"), 18mm (3/4"), 25mm (1"), 40mm (1 5/8") Having no grain it cuts and routes cleanly, the thinner boards can be curved to a fairly tight radius by hand and if needed, ripping grooves in the back of the sheet allows the radius to be tightened further. Fabrication is best done by gluing and screwing with countersunk softsheet screws. Working MDF gives off quite a bit of fine dust and owing to the makeup of the material you should wear respiratory equipment (formaldehyde content?), a particle mask at least. HTH, David
------------------ David Fisher D.A. & P.M. Fisher Services Brisbane Australia da_pmf@yahoo.com
Posts: 1450 | From: Brisbane Queensland Australia | Registered: Nov 1998
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MDF is used extensively in the production of cabinets or " caseworks" as it is commonly referred to. Prior to getting into the Sign/graphics area, I had a company that produced toy lines and we used MDF a lot. It stands for medium density fiberboard. It has a more dense compaction over particle board and produces a finer finish when properly prepared.
We use a lot of mdf as a substrate for dimensional lettering for Interior use only! As eluded to, it absorbs water terribly if exposed so it does not and should never be introduced for exterior application.
We use it as an inexpensive alternative to products like gatorfoam for interior use because of it's hard characteristics and depth achieved for the money you pay.
Hope this helps!
Drmwvr
PS..just remember that as the letter gets larger we change our application to the wall. It does get heavy!
------------------ Robert Beverly Dreamweaver Graphics House Arlington, Texas
"Dreams come a size too big so that we can grow into them"
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