marshon
New Member
I'm soooo frustrated and fu*ked off that I thought I might share the following ......
I'm building a hybrid backpack, I wanted something between a P1 and an AVP style, so I started planning an armature.
I came across this PDO from movieman and thought I could adapt it to my needs.
I assembled the PEP as usual and left out bits / added bits to produce a basic armature.
Three days work with the two outer and two inner coats of resin
...... now .....
I would normally give the internal surfaces an additional coat of resin and rough matt to strengthen it BUT it would be very fiddly and difficult to get into the little nooks and crannies, so I decided to use polyurethane gap filling foam. I've done this before without problems and you normally end up with a light, strong armature. However this time something went VERY wrong! The valve on the foam can stuck open so it dumped all of the foam into the shell. No big deal I thought, just a bit of carving back to do. I left the backpack for 24 hours to cure. When I went back to it, the foam had dried to a nice comforting hard finish, but there appeared to be some still un-cured material that had collected at the base of the back pack. I started to trim back the excess from the surface and a hole about an inch in diameter appeared. I peered in to see that the foam had formed a 1" thick outer cured part and the rest was hollow!
As soon as the air hit the un-cured foam it began to expand. Cool I thought that should fix it! I left it and went make a coffee.......... BANG! (load noise from the workshop). I rush up to see what the noise was ..... the expanding foam had plugged and sealed the 1" hole and then continued to expand until it SPLIT THE RESIN AND THE PEP!
Disaster! Now I have to start again having wasted 3 days work, a can of resin and a can of foam ....... bollox.
I'm building a hybrid backpack, I wanted something between a P1 and an AVP style, so I started planning an armature.
I came across this PDO from movieman and thought I could adapt it to my needs.
I assembled the PEP as usual and left out bits / added bits to produce a basic armature.
Three days work with the two outer and two inner coats of resin
...... now .....
I would normally give the internal surfaces an additional coat of resin and rough matt to strengthen it BUT it would be very fiddly and difficult to get into the little nooks and crannies, so I decided to use polyurethane gap filling foam. I've done this before without problems and you normally end up with a light, strong armature. However this time something went VERY wrong! The valve on the foam can stuck open so it dumped all of the foam into the shell. No big deal I thought, just a bit of carving back to do. I left the backpack for 24 hours to cure. When I went back to it, the foam had dried to a nice comforting hard finish, but there appeared to be some still un-cured material that had collected at the base of the back pack. I started to trim back the excess from the surface and a hole about an inch in diameter appeared. I peered in to see that the foam had formed a 1" thick outer cured part and the rest was hollow!
As soon as the air hit the un-cured foam it began to expand. Cool I thought that should fix it! I left it and went make a coffee.......... BANG! (load noise from the workshop). I rush up to see what the noise was ..... the expanding foam had plugged and sealed the 1" hole and then continued to expand until it SPLIT THE RESIN AND THE PEP!
Disaster! Now I have to start again having wasted 3 days work, a can of resin and a can of foam ....... bollox.
Last edited by a moderator: