My ancient giant chest freezer still freezes, but the plastic underside of the lid, which holds the insulation and seal in place has cracked to shit and pretty much fell out the other day. It's way too old for replacement parts to be available. Was getting ready to just drop $700 on a new one, but figured I could find a way re-secure the thing and I'm thinking like 8-10 long plastic bolts right through the outer metal lid with some big fender washers on the underside cover should be enough to hold it in place. I'm thinking plastic since it shouldn't conduct the cold out or heat in. I was thinking toiled seat bolts, but they're all in the 2.5" range. Hard to get an exact measurement, but it looks like I need at least 3-3.25".
I'm striking at at the usual places. I found some 8mm metric polypropylene ones on amazon that will probably work, but I figured someone here will know a cheap source for what I actually want.
Other thought I had, but I can't remember what they're called or exactly where they're used. I can picture them but no clue where I've seen them before. Basically a plastic serrated or ribbed rod with a flange on one and and then a washer would slide on the loose end and the serrations would keep it from backing off. Almost like a zip tie. Maybe something used in insulation or ceiling tiles or something? This one is driving me nuts but my google fu is failing me.
Edit:
Almost like this, but I swear I've seen them with a plate/washer on the bottom for sandwiching materials
I'm striking at at the usual places. I found some 8mm metric polypropylene ones on amazon that will probably work, but I figured someone here will know a cheap source for what I actually want.
Other thought I had, but I can't remember what they're called or exactly where they're used. I can picture them but no clue where I've seen them before. Basically a plastic serrated or ribbed rod with a flange on one and and then a washer would slide on the loose end and the serrations would keep it from backing off. Almost like a zip tie. Maybe something used in insulation or ceiling tiles or something? This one is driving me nuts but my google fu is failing me.
Edit:
Almost like this, but I swear I've seen them with a plate/washer on the bottom for sandwiching materials
Wonder if 10 of them would be enough to hold the cover in place. With the insulation I doubt it weighs more than 2-3lbs, but it'll be subject to a little stress every time it's opened, plus the constant freezing temps. What ultimately caused the demise of the cover was it started to pull apart on one corner and started to freeze/frost over inside the lid. The more it did that, the heaver it got and it dropped more and let more moist air and....repeat, repeat. It happened over time until I eventually noticed that the lid was getting heavier. Eventually it just failed and fell off. 
