Got a few problems with some material that just arrived
I order: 6 – ½” 4’ x 6’ HDO pre-finished yellow diamond grade reflective vinyl panels. (these are to be highway signs)
The edges and backs are not finished, and the material looks like MDO. I’ve got the paper work to prove that this was may request.
I pretty much have to accept them the way they are……they traveled 1000miles and took 5 weeks for delivery. I’ll be asking for a rebate for time/materials to finish the edges and backs. (that’s a reasonable request ……..no?)
Question: what is the visual difference and approximate cost difference between HDO & MDO I’ve only ever used MDO and the local lumber don’t stock HDO.
Posted by Chuck Peterson (Member # 70) on :
I've heard of HDO (high density overlay?) but don't think I've actually seen it. Sounds like it might be something to look into with the poor quality of MDO these days. Sorry, I can't answer your question.
Posted by Bill Preston (Member # 1314) on :
Hi, John,
As far as I know, the only difference between MDO and HDO is the amount of gaps or flaws you would see along the edges---MDO having more, and HDO having less. Whether there is any difference in the wood laminate material, I don't know.
HDO would I guess cost more, but never having used it, I couldn't say what the cost differece would be.
Can't advise you on the rebate issue, either. Guess it depends on how clear your supplier was about what you were getting.
Posted by Kent Smith (Member # 251) on :
High Density Overlays are almost 1/16" thick wheras MDO is much thinner and HDO is typically 7 ply. Edge voids are similar to MDO as it is the overlay that changes not the quality of the plys. This can vary greatly between manufacturers.
Posted by John Martin Robson (Member # 1686) on :
Talked with my suppier/sign company this morning. They say you don't need to finish the backs or edges.....they say the Dept. of Transportation (Alberta)specs this all the time.......is this the case in other areas?
anyone?
Posted by Bill Preston (Member # 1314) on :
John, if that material is indeed MDO, then I can't believe they told you it doesn't need to be finished off. Are you seeing laminations and glue on the edges, and is the back at least primed?
Maybe this is some other material------ and what they said is true--- but I wouldn't bet the farm on it.
Posted by John Martin Robson (Member # 1686) on :
more problems........I just started to finished the edges of this MDO/HDO.....whatever the f...k it is. The wood filler is reacting with the reflect vinyl.....take the yellow right off the surface.......I'm f..king fuming now. Even if I tape the edges the filler will find its way under the tape and on to the vinyl...another thing I noticed is there are five plys to this 1/2" material.....I thought I read somewhere that standard HDO @ 1/2" would have 7 plys.......is this correct....?
Posted by Steve Purcell (Member # 1140) on :
The HDO will have a thick, resin overlay with a waxy film, and must be properly cleaned & prepped (like fiberglass) before applying finishes.
It is murder on saw blades.
The edges are open ply.
Posted by donny pavolini (Member # 2244) on :
I'm in total agreement with the last post as far as the waxy stuff on the HDO. A company by the name of TRAFFIC CONTROL PRODUCTS sells barricades to municipalities in the surrounding area.There's not a stitch of paint on the back of one of the barricades they sell. Diamond grade reflective on the face, HDO on the back. When I asked an employee there why the backs were bare he told me that HDO is plenty weather-proof on its own. From my experience working with HDO to paint it I sand,wipe down with xylol, prime with OIL PRIMER, then finish with OIL.
It works great. I am a little baffled about the wood filler reacting with the vinyl though. The plywood I buy for 1-sided signs has pre-primed MDO on the front and HDO on the back. My vendor says the HDO is a little resistant to paint and I've found that to be true of latex paints. That's a bummer for me because that's my favorite type of primers.
Hope this helps and good luck.
Posted by John Martin Robson (Member # 1686) on :
Donny
On these barracades......did you happen to notice the edges......were they finished or protected some how. Its the edges that I'm concerned about......I'm not going to bother with the backs of these sign panels.....but I can't leave the edges exposed.
