Simons WRAP16

[huntvambo]

Does anyone else have any problems joining Simons WRAP16? It's an MDF based paper wrap that's 25mm across the front face and 20mm deep.

It cuts on my Morso without any problems but when I come to underpin (CS88) I just can not get a good join it either gaps on the front inner corner or on the back edge corner. I've tried different wedges, different wedge positions and got through two lengths without an acceptable result. What am I doing wrong?

The moulding before joined perfectly and the moulding after was fine, they were both wood, so I'm happy it's not my kit that's at fault, maybe just me!!!

Thanks in advance.

Paul

[framejunkie]

I've not used MDF mouldings, but it sounds like an issue with the cut to me. If the morso is not cutting perfectly flat surfaces its often because the moulding is rocking as the blades come down. Does the wrap on the moulding go right round onto the underside? If so then that could be the root of the problem - either the paper wrap is proud of the underside of the MDF or the moulding has a thin cut-away to allow for the wrap on the underside - it is unlikely to be micron-accurate. If you cannot cut this moulding upside down, figure out how its rocking and add a 'shim' of thin paper - eg masking tape - until you have it flat. I think these types of mouldings are best cut on a really good circular saw, but you are looking at £££££££

[huntvambo]

Thanks Simon,

The paper wrap goes all the way round the moulding, it likes very well finished - I tried cutting upside down but it didn't make any difference!

Which ever way I cut I can't detect any rocking, front and back faces seem pretty flat. If I place the two mitres together they look good, it's only during the underpinning that the problems appear. I wonder if it's because of the density of the MDF does not compress but pushes out instead deforming slightly.

I think I'll take a lesson from this one, put it to one side for now, and complete the job with a wood moulding that's very similar in appearance but more expensive!

Paul

[Merlin]

We use WRAP 18, 20, 22 & 24 here.

Make sure that the top foot is close to the moulding.

We have to turn up the pressure on the underpinner to get a clean insert of the wedges.

Otherwise it is a good mover for us.

[Not your average framer]

I have a set of chevron samples for the whole range, which I cut and joined myself. Although I did not have any problems with these, I chose to place a number of wedges across the width and got a nice tight solid joint. MDF is a harder material for the wedges to penetrate, because of there is no wood grain in line with the inserted wedges.

What type of wedges are you using? I used hard wood wedges, which have less of a tightening effect when inserted, as I figure the MDF benefits from not creating un-necessary internal stresses within the material.

I'm not a big fan of wrapped mouldings, but the Simons are lot nicer than most I have seen. They cut cleanly, appear to have a good durable finish, (unlike some that we see) and also feel really strong and ridgid, so they should be suitable for quite reasonable frame sizes.

[huntvambo]

I use genuine Cassese wedges.

I started with 10's, one close to the inner corner and 1 1/4 way from the back corner. Then still with the 10's I moved the back corner to 1/2 way. Then I tried 7's in the same places and then 2 x 5's in the same places - didn't really see any improvements.

I'll give the 10 HW's ago.

I've now done both original jobs with an alternative wood moulding so at least the customers are happy.

I agree that these Simons wrapped mouldings do look and feel good and the price is very competitive but not when you're scraping length after length. I'll carry on with what I've got left and try and resolve my issues.