Impluse heat sealer for thermal urethane

[kach22i]

Impluse heat sealers for thermal urethane

I have some samples of heat sealable fabric for making waterproof bags (nylon base 420 denier with a nice thick urethane coating one side). They said you can just iron it with a houshold iron, but that leaves something to be desired. Problem is both sides should be heat activated at the same time and pressure kept on after the heat is removed until it cools. An iron can't do that, and an iron has a hard time doing straight lines (mine are two feet long). By the time I get it to seal well it starts to bubble and ruins the finish. If I go over it several times it ends up stiffing the fabric (bad for my application).

My first product choice would be the T-Clamp a $3,000 Vertrod Style by Therm-O-Seal, but I can't afford it.
http://www.therm-o-seal.com/equipment.handsealers.html

My last choice is $40 from Harbor Freight, might be better off with the iron.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43477

The local rental place has nothing to rent me, the local tent and awning place only sews things and is expensive.

Any suggestions besides Craig's List and E-bay?