I've wanted to do this since I built my 290s about three years ago, but only now I bought the foam
and found the time to dive into this project (also doing my subs and stage monitors at the same time).
I found a neat way to attach the foam to the grills so I thought I'd share it here. All my cabs have
perforated metal front grills already and I only needed to attach the foam behind it.
I am using a black rubber based spray paint from Wurth http://www.superiorcarcare.net/w890971.html.
I found it to be very easy to work with and by the method explained in the attached pictures it serves an excellent adhesive to attach the foam to the metal grill.
Shown in the pictures, is the last grill to be 'foamed' in which I combined scrap pieces of the foam.
As can be seen, the seam is completely invisible.
This is how the original plain perforated grill looked:
Here preparing the foam, holding the two pieces together with few cuts of masking tape:
Laying the back jig/template of the grill on top of the foam as a guide for cutting:
Foam cut:
Flipping the complete template and foam. Now ready for attaching the grill:
Spraying the grill. Building a nice and tacky layer:
Immediately laying the sprayed grill on top of the foam. This causes the adhesive to 'drip' down a little into the foam and grip it positively. Straight away weights are added to insure good and even contact throughout the whole area of the grill:
After initial curing of about 20 minutes weights are taken off, the grill can be lifted from the template (and in this case, the masking tape carefully removed):
Here is a view of the finished work from the back side:
Here a better picture of the front side:
And a close-up:
