synthetic moulding


Sep 5, 2006
Buderim, Queensland, Australia
Hi All,

I am a newbie here so please forgive any unintentional errors. I have recently started making frames for resale in my own photographic retail store.

I have noticed that one of my moulding suppliers has a category called "synthetic". I am curious about the methods for cutting and joining this type of moulding.

I have a morso guillotine and manual v nailer. The main reason I am asking is I have a project coming up that will be 6 framed mirrors approx 850mm x 600mm and the synthetic moulding has the preferred design.

Any help would be much appreciated.

Let me be the first to welcome you to the G. Feel free to ask any kwestions and dont hold back. I have been on here for a while and framing for longer, yet I learn something new each day.

Ok the synthetic moulding, I have not worked with any. But I am familiar with it. From my knowledge there are two types. The first would be poly or foam mouldings. These mouldings are light weight and you need a chopper to cut them as a saw will melt them. You also need a special glue for the corners. The glue actually melts the corners together.

The second is wood (saw dust and glue) MDF multidensity fiberboard. In the states this is found in many hardware stores. This moulding is much denser and heavy-heavier than most wood mouldings as the glue adds weight. This is best to cut with a saw. This does do a number on blades as the glue is hard to cut thru. Here we find these as the base and then veneers are overtop the MDF.

Hope this helps. I beleive both can be v nailed with a manual pinner. Good luck and welcome once again.

re : "poly or foam"
can be cut---should have a special blade and the cutter should wear a resperator....if those 2 dont put a stop to you, press on!!!!!!!!!
I use some extruded polystyrene mouldings, and like them for some applications.

Slow cutting could make melting a problem. However, they cut just fine on our 3450 RPM double miter saw, which is foot pedal operated. We operate the foot pedal quite fast for these mouldings, which makes a clean cut. Then we sand the miters on our hand-turned sander. The motorized sander is too fast, and melts the plastic.

The adhesive should be cyanoacrylate (Super Glue); I prefer the gel or "gap-filling" type. Our miters do not have gaps to fill, but that viscosity does not drip as readily as the watery type. If any adhesive got on the finish, it would be ruined.

I recommend using a mechanical fastener, and would not rely on glue alone, even though it makes the miter stronger than the plastic around it. If you use an underpinner, it will work well on polystyrene mouldings. Remember that the plastic does not compress as wood fibers do, so each insert will expand the miter's width, and could cause open corners at the front or back. So, I suggest using fewer inserts on plastic. The same is true for MDF.
I just joined some poly stuff for an outside sign.

If you use it with the poly glue remember you can not get ANY on the face of the moulding.

In the same way it will melt your corners together it will also melt off the face if it makes contact. Makes that fourth corner a bit tricky if you are by yourself.

Overall, I am not a fan but it has it's place.

Welcome to the G!
Thanks every body. I think I will try to get the customer to choose a non-synthetic molding.It seems that the weight of your opinion is that the synthetic is a bit tricky to deal with and I don't need any more complications in my life than I have already got!
This forum appears to have some really nice people on its boards - thankyou to all who gave me a warm welcome.