Polycarb Design?

[bigapple]

i went over to my local home depot and bought some sheets of lexan but im in a quandry... i understand how im gunna do the basic 5 sides for the box but im unsure how exactly im gunna seal off the lid... any ideas on how i can do that? i want to have the top to where i can get inside the box if i need to mess with my plates or my connections... i could completely seal it but if something goes wrong then im screwed and have to bust it open

thoughts or ideas?

[Painless]

Could you get either some liquid rubber or some type of air-tight sealant and build a good lock into the lid?

[smartHHO]

I was thinking, lay a nice bead of silicon down, and find a good lock down latch and hinges maybe for it. Something in the direction. so you can unlatch it, and the silicon seal should pretty good on the seal for the container. I have thought about that problem also for a bit. You set up the latches or hinges with a slight clearance before you put the silicon down. Not too big of a bead but one that definitely covers. Let it stick and dry to the bottom half. Then shut the lid and lock it down. That is the best way I can see doing it. Unless you want to just put the silicon on there and clamp it down for a tight seal. Then if you have to get back in, you just put it apart and clean off the silicon for the next seal job.

[Stratous]

lexan does not like having direct pressure from bolt heads or screw heads. It will cause cracks, so what ever you do. Dont screw the lid down. Perhaps using some latches will work better

[smartHHO]

lexan does not like having direct pressure from bolt heads or screw heads. It will cause cracks, so what ever you do. Dont screw the lid down. Perhaps using some latches will work better

Could get some kind of straps that go all the way around the box and then apply the silicon bead all the way around. That would definitely get a tight seal and avoid any screws.

[bigapple]

def good ideas... anyone have any idea where i can get any of these latchdowns? in the hinge section of hardware stores maybe? and i think those latches screw down with drywall screws... if i make even small pilot holes to put those in, would it still cause it to crack? also, if i put these latchdowns on the box, wouldnt that cause the lid to flex? i was thinking of getting some small steel bars to go across the top to prevent flex and i was wondering if anyone had suggestions for that as well

stratous ive seen uve made some lexan boxes and i was wondering how exactly u make them accessible to the inside or if u just have them bolted or sealed down

and also suggestions for a good solvent cement for polycarbonate would be good... if i have to order something i will, but id rather get some locally at ace, home depot, or lowes... ive seen some silicone sealants but im sure those arent as durable and u could probably pull them apart if u tried

all the suggestions are much appreciated guys

[Stratous]

You better order the solvent for the lexan, unless your local store sells weld-on products. Poly is very difficult to "glue" so its best to be chemically welded or bonded to itself. I originally used screws and a rubber seal to make the box lid, but soon realiized that the direct pressure from the small screw heads made the lexan crack. I then tried using permatex to make a gasket using screws to snug the lid down. The permatex wouldnt stick to the poly very well and leaked. After my 4th box, I got tired of fixing things and decided to permenantly weld the lids on. Currently, thats what I have done and will keep it that way until I need to build a new box.

You can get poly solvent here. http://www.ipscorp.com/industrial/index.shtml or www.craftics.com

[bigapple]

does anyone know if poly or acrylic hinges exist? if so then i can make a decent seal with a permatex gasket sealer along the top and put a nice latchdown on the other side... if not that, i was thinking of doing something along the lines of this to get the lid on tight (see below)... only thing being that poly flexes which could be an issue... ive also thought about just drilling holes and using nuts and bolts to attach everything to where i wont have to use drywall screws to drill into the poly... drilling holes seems a good bit safer... most importantly, id really rather not weld it closed cuz then i cant change or clean anything and i want to be able to get in it

heres a side and top view... the black circles are screws with washers... im thinking if i do that, i will need to double up the layers or add some extra metal to keep it rigid to where it doesnt flex when i bolt it down... i really really dont want to have to completely seal it so any other suggestions will be greatly appreciated

[bigapple]

finally figured it out! check out my new post here

http://hhoforums.com/showthread.php?p=9808#post9808