Epoxy or polyester?

[Stemar]

I need to make some small boxes, roughly 30 X 20 X 10 cm. They'll be used to hold tins of food to keep them from wandering around the food locker when heeled and to lift out when access is needed underneath.

I'll be using 5mm ply which I already have, but I don't have the necessary skill or patience to use anything more than butt joints, which I wouldn't trust. I don't want to fillet the corners as it wastes space.

Would polyester resin be up to the job of gluing and reinforcing the corners with light glass tape? I've used epoxy for similar things in the past, but the cost is putting me off

 

[eyehavit]

Personally, I keep glass fibre and associated resin products as far away from food as possible.
Why not make your boxes from say 1.2mm thick aluminium (dry food product) or ss and get your local sheet metal folder to form the boxes and lids?

 

[Bodach na mara]

I note that it is cans of food that they will store, so concern about resin products may not be an issue, however why not look for a ready-made solution? My wife got fed up with the shambles that the cool-box fridge gets into and found a solution in a hardware shop where she found some small plastic boxes. They are similar to the large boxes I use to keep all the baot stuff over the winter, but only about 30 x 10 x 10 cm. Elsewhere in the boat, the previous owner has made intelligent use of plant troughs (from a garden centre). They also used a small fish box (look about the dump at a fishing port) under a hatch in the berth to create a top level to a deep locker. The lower level is accessed via a door in the vertical panel.

 

[30boat]

Polyester does not adhere well to wood.Why don't you glue the edges of the plywood panels with polyurethane glue with some panel pins for good measure?.I made kitchen drawers like that 7 years ago and they're still going strong.

 

[Guest]

Of course they would be ok ... with either resin ... and I would glue with the same resin you are to use to "cloth" up with once made.
If you go to a model shop - you can buy rolls or lengths of woven glass "tape" ... used to cover wing joints on model airplanes ... far better than chopped strand mat ... you may get it in Resin suppliers as well ...

A neat trick to help with this ..... Glue up boxes .... get a hot-melt gun and fillet around the joints inside ... a single bead ...
Take measured cut length to glass tape and tack with super glue the end at one corner .... stretch it and tack other end on other corner .... do this with all 4 tapes ... making sure you stretch well and keep it flat to the edge ... Then you can stipple the resin in without lifting the tape away etc. each time ... Reason to stretch it ? The resin will cause the tape to slacken so needs prestretching to combat this.

There is another less painful way to do this job .... buy small vegetable plastic trays .... that way they have ventilation via the mesh and also are ready-made ...

I know this is a diversion from the topic slightly .... but if you use bigger plastic boxes / veggy trays under bunks / 1/4 berths - you can join the ends of each box to each other with short piece of line ... so drag out one - pulls the others out as well .... no more reaching back with a boat-hook etc. Or have each with a line separate to the access point !

 

[paulrossall]

I think you ned to get down the local cheapo hardware/DIY store and buy plastic containers. Cheap, loads of diferent sizes, easy to clean, light. Thats what I use for storeing my tins. I don't mean Tuperware-type, biger, robust.

 

[Blueboatman]

I would suggest that you actually do use epoxy plus a thickening additive(eg microballoons)which,combined with your simple butt joins will provide a strong structure and easy-clean smooth internal corners..The swindleries usually have the relevant free guides for west and sp systems to give you a better idea.
One other thing.If you mark out your 5mm ply with a sharp knife before cutting you will have much neater cut edges.
I would have thought 25 quids worth of epoxy and additive will do it -still want to invest that amount to do it right?

 

[Skyva_2]

IMHO epoxy/filler is easier to work than grp/tape, though more expensive. Microfibre filler give a stronger joint than microballoons, though the balloons are good for fillets. Colloidal silica thickens the mixture and stops it running. Use the slow setting hardener, some of the 'quick' stuff is only good for 10 minutes.

If you are not put off by all this chemistry it is straightforward, just read the instructions very carefully and wear gloves!

Plastic boxes would certainly be easier.

 

[Poignard]

If you can bear a visit to the hell on earth called IKEA Croydon, it's the sort of thing they might sell very cheaply. [Probably got some weird Scandinavian name like JOBI or YUKKI]

 

[Stemar]

Thanks all.

Ikea does sound like a good idea, I couldn't but the materials to make a lot of their stuff for the price they sell it at, but it'll be Edmonton or Brent Park rather than Croydon. I'm a North Londoner and my A to Z has blank pages with "Here be Dragons" south of the Elephant & Castle!

I've looked for plastic boxes, but most of the ones that are the size I want waste a lot of space by shaped to stack in or on each other, hence the thoughts of making boxes.

 

[William_H]

To answer your first question. Polyester is cheaper and easier to use but won't stick to wood so well. Epoxy sticks much better.
One trick you might consider is fibreglass tape around the outside of the top of the box in a continuous strip perhaps several turns. This would be especially desirable if you use polyester resin. if you just run a strip of tape up the outside of the corners it will be difficult to get a tight bend so you get air bubbles/gap and the tape will rely on adhesion to the wood. Similarly long strips from one side down to the bottom across and up the other side will provide strength for the weight in the bottom. Ideally use thinner wood and more glass.

You will find that it takes some time for the styrene small to dissipate from polyester so you wouldn't want to use the boxes for a while. I am not sure about epoxy smells.

I bought a plastic box for 1 quid and a bit yesterday with lid. It is about 40 by 30 by 16 cms but I see what you mean about wasting space with lips and overhangs for strength. Easy to clean however. No don't ask where you might be a long way away from Fremantle. good luck..... olewill