tsgstl
New Member
I have been making these foam T's to mount on roofs of trucks for years now. Each time out of trial and error I adjust my technique. The customer likes them made out of foam in case they come off they will not do damage to oncoming vehicles whatnot. I have tried leading him to a different decision but he is stuck on foam. They usually fail by the posts that go up through the foam stripping and pulling loose. The last bunch I made I recessed plates in the top (max metal) and bolted them through the entire foam sandwiching the other end with another piece of max metal at the bottom. I think this is the best way yet, but I am always into new suggestions with these.
MY QUESTION:
This new method creates a void obviously at the top. I used a thin 1m piece of pvc to cover the hole and then covered that with drywall tape. I then have them hardcoated. My problem is that somehow during or after hardcoating air must escape through the hardcoat creating a small bulble like effect around the piece of pvc. I saw last night on a HO train layout video that a guy used plaster sheets (what they use for arm casts) would this be a better solution? I'm open to any ideas to avoid this problem. I tried expanding spray foam and it was just to hard to contain and to time consuming to wait until dry to cut off.
The bottom is just a .080 sign blank that I thread through (thread all that goes all the way through the top) after hardcoating, then they get painted by the customer.
I have another batch of these about ready to pick up from my foam supplier and 2 heads or more are better than one.
MY QUESTION:
This new method creates a void obviously at the top. I used a thin 1m piece of pvc to cover the hole and then covered that with drywall tape. I then have them hardcoated. My problem is that somehow during or after hardcoating air must escape through the hardcoat creating a small bulble like effect around the piece of pvc. I saw last night on a HO train layout video that a guy used plaster sheets (what they use for arm casts) would this be a better solution? I'm open to any ideas to avoid this problem. I tried expanding spray foam and it was just to hard to contain and to time consuming to wait until dry to cut off.
The bottom is just a .080 sign blank that I thread through (thread all that goes all the way through the top) after hardcoating, then they get painted by the customer.
I have another batch of these about ready to pick up from my foam supplier and 2 heads or more are better than one.
