Patching cracked trays?

[Donald Qualls]

High Density Polyethylene is bad news -- there is no glue that I know of that will stick well on HDPE. Silicone sealant (the clear variety) is probably the best bet, or else "plastic welding" with a heat gun and filler of the same material (needn't be identical molecular weight range, but should be close -- you could cut strips from a dollar store cutting board).

 

[Michel Hardy-Vallée]

I've used JB WaterWeld with success to fix leaking gutter drains, and I used it too to glue the rubber ends of my plastic tongs back on the handles:
https://www.jbweld.com/product/waterweld-epoxy-putty

It's an epoxy putty, cures even under water, and adheres to pretty much anything. Should be in any good hardware store.

 

[Ariston]

Drill a small hole at each end of the crack before attempting a repair, to stop the crack propagating.

This is good advice. I did this and used good old-fashioned caulk. Who knows if it will hold against developing chemicals.

 

[Paul Howell]

Considering the size of the tray I would attempt to repair, if the caulk does not work go the auto body shop and buy a fiberglass repair kit. Cut the fiberglass cloth to fit over the crack by a couple of inches, on both sides, start with the bottom by adding a layer fiberglass over the crack and painting on the resine, be sure and use a green pad to scuff up the surface so the resin will adheah. Once dry, on the top of the tray pour resin in the crack, then layer the fiberglass over the area, paint with resin.

 

[Steve Goldstein]

Update: I heard back from Omega-Brandess today - the trays are thermo-formed from a high-molecular-weight polyethylene. Just for giggles, I sent a note to the material manufacturer asking for their recommendations. I'm leaning towards the Gorilla Waterproof Patch and Seal Tape I linked to in post #15 and sent Gorilla a question regarding the product's chemical resistance. The PermaBond stuff Roger found looks perfect but I can get the tape more easily and cheaply, so I'll probably start there unless Gorilla says that acids to pH 4 and/or alkalis to pH11 are problematic.

Yes I'm being obsessive about fixing this, but it's hard to justify $90 for a new tray I might use once in a few years...

 

[Roger Thoms]

Yeah, I did a little more searching and the Permabond product isn’t cheap. If the Gorilla Tape works you might have the makings of an infomercial.

Roget

 

[RalphLambrecht]

Has anyone ever successfully patched a cracked plastic developing tray?

I just got some 20x24 Cesco trays at a very good price. One of them has a crack about 4” (100mm) long where the bottom curves to the sidewall. These trays are a softer plastic than most others I have. Would something like Gorilla tape or FlexSeal do the job? My concerns would be chemical resistance and strength.

Probably best to get yourself a new set of trays.

 

[glbeas]

You could use the old trays as a mold for a new fiberglass tray. Paint the outside with the epoxy resin, lay on your fiberglass mat, epoxy, more mat, until you get a good thickness, finish off with the epoxy and let it cure. If that old tray is hdpe plastic the fiberglass should pop off with a little persuasion. Might need a coat of resin inside to smooth it all out.

 

[Donald Qualls]

You could use the old trays as a mold for a new fiberglass tray. Paint the outside with the epoxy resin, lay on your fiberglass mat, epoxy, more mat, until you get a good thickness, finish off with the epoxy and let it cure. If that old tray is hdpe plastic the fiberglass should pop off with a little persuasion. Might need a coat of resin inside to smooth it all out.

If you already do fiberglass work (boat building, custom auto body, etc.), hence have the cloth, mat, resin and hardener (and protective gear) on hand, this is actually a very good suggestion to be able to make multiple trays at very reasonable cost, but you'd want to start by molding the inside, to make a plug, then mold up the new tray over the plug to make the inside of the new tray (the important surface) match the inside of the original. If you already do fiberglass work, though, you'd know this...

Marine type gel coat should be a very good inner surface for a tray -- inert to almost everything. I've seen this method used to line wood-built darkroom sinks and hot tubs...

 

[VinceInMT]

I used the two part epoxy made specifically for plastic for this repair. Being a belt and suspenders guy I covered the outside with a piece of Gorilla duct tape.

 

[bsdunek]

I've used JB WaterWeld with success to fix leaking gutter drains, and I used it too to glue the rubber ends of my plastic tongs back on the handles:
https://www.jbweld.com/product/waterweld-epoxy-putty

It's an epoxy putty, cures even under water, and adheres to pretty much anything. Should be in any good hardware store.

Yep, good old JB Weld. Best stuff I've found.

 

[AgX]

High Density Polyethylene is bad news -- there is no glue that I know of that will stick well on HDPE. Silicone sealant (the clear variety) is probably the best bet, or else "plastic welding" with a heat gun and filler of the same material (needn't be identical molecular weight range, but should be close -- you could cut strips from a dollar store cutting board).

Aside of surface treating by ionizer, there are respective primers for use with cyanacrylates and even such that need no primer. Though all these glues are for industrial use.

 

[Billy Axeman]

Probably best to get yourself a new set of trays.

Finally someone with a sensible approach.