I am nearing my wits end trying to plastic weld a leaking black HDPE fuel tank on my Poulan 21inch self propelled model PR65Y21MA. This is a clamshell-type tank whereby the top 1/3 of the tank is apparently ultrasonic welded (or solvent cemented?) at the factory to the bottom 2/3 of tank. I got the mower used/free so am unsure how the first crack (3/8 inch vertical/perpendicular to the clamshell seam) developed. As I fixed the original crack I then noticed additional leaks along the factory weld. I am using a Harbor Freight plastic welder tool. I test for leaks by blowing my breath into the tank (fuel line attached to tank drain fitting) with cap in-place, spraying the outside of the tank with soapy water and then visually observing for bubbles. It seems no matter how I melt/move the welding rod/material, I "chase the leak" to another location. Whack-a-mole!!
On youtube (I know--be careful what you believe)I saw a guy whose technique seemed to make sense. First he melts at the leak location, then he adds material from the rod and "mushes around" the melted material at the leak location. Makes sense to me, but is there a better technique?
Also, is my soap bubble testing technique improper (too stringent, i.e. "false fails") for this problem? During my last failed test, there were 3 areas that produced bubbles. I filled the tank to the very top with water and sat the tank in a basin overnight. By morning there was approximately 1 Tablespoon of water in the basin, i.e. the tank leaked but very minimal. I could probably live with this minor leakage--just fill the tank to no more than 2/3 full before mowing, then if tank is filled slightly above 2/3 even with fuel "sloshing around" while mowing there should be little or no leakage/danger. Main caution would be to never store the mower with fuel above 2/3 level.
Any suggestions would be greatly appreciated.
On youtube (I know--be careful what you believe)I saw a guy whose technique seemed to make sense. First he melts at the leak location, then he adds material from the rod and "mushes around" the melted material at the leak location. Makes sense to me, but is there a better technique?
Also, is my soap bubble testing technique improper (too stringent, i.e. "false fails") for this problem? During my last failed test, there were 3 areas that produced bubbles. I filled the tank to the very top with water and sat the tank in a basin overnight. By morning there was approximately 1 Tablespoon of water in the basin, i.e. the tank leaked but very minimal. I could probably live with this minor leakage--just fill the tank to no more than 2/3 full before mowing, then if tank is filled slightly above 2/3 even with fuel "sloshing around" while mowing there should be little or no leakage/danger. Main caution would be to never store the mower with fuel above 2/3 level.
Any suggestions would be greatly appreciated.