Signfoam repairs

I would probably prime the piece first before filling in any blemishes. There is a tendency for there to be a "slick shiny spot" where the repair is made if you don't prime first.

Just my personal experience.

Depending on the type of repair, you may want to try creating your own "filler" by rubbing two scrap pieces of HDU together and mixing the dust with a urethane glue such as Gorilla Glue. The repair tends to look more natural than if you used body filler. One reason is that HDU and body filler have different densities and won't sand at the same rate. By using the "homemade filler" instead, the two densities are closer and the sanding will blend better.

 

You can use the routed "dust", but I wouldn't use Elmers wood glue. The glue dries at a different density. You want to use a urethane glue because it has a lower density and will sand away slightly faster than the substrate.

 

sign foam repair

Thanks for the info GT.I agree you should always prime the foam before filling blemishes.If you dont,you will get a shiny spot.I have always used the body filler or spot putty to fill the foam.you have to be careful to not over or underfill the hole or you will be sanding all day.how does that mixture work for rebuilding edge and corner damage.This seems to be the hardest to repair.
Thanks
Brian