Defrost plenum repair: before & after

[70Bronco]

Broken defroster plenums can be repaired. All 4 tabs on my 66 Belvedere were broken off. Luckily, I have a friend who spent many years working with plastics. He has the know-how and an elaborate plastic welder to get the job done right. While working, he explained that you can’t glue that type of plastic and you gotta use the exact same type of plastic when welding. When he finished, these pieces were just as strong, even stronger really, than when they were new.

 

[Demonic]

Thanks for posting that. Looks great. Would that happen to be ABS plastic?

 

[70Bronco]

Thanks for posting that. Looks great. Would that happen to be ABS plastic?

Good question. It is not ABS plastic. It is the original 1966 defroster plenum. My friend told me what kind of plastic it is, but I can't remember the name, but it is a very common plastic still in use today.

 

[70Bronco]

Thanks for posting that. Looks great. Would that happen to be ABS plastic?

The defrost plenum is made of Polyethylene.