WVvan
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Acrylic lid continued:
It will be easier for me to describe what I'm doing if I include a diagram. This is a layout of all the pieces I've cut from the acrylic sheet.
This is a side view. Pieces "Top A" and "Top B" have a slight incline from the end pieces to where they meet in the middle. The high point in the middle is where the vent tube will be installed.
I had previously joined the edge of "Top A" to "Side A" using Weld-On #3 solvent cement and capillary action. This was my first try at joining acrylic and I was more than happy with the results. I let it set about a day then removed the clamps. The joint looked perfect and I stressed it without any problems.
Everything looked good until I started dry-fitting the other pieces. That's when my previous bone-headed mistakes came back to bite me. I should have known better.
In this picture "Top A" is joined to "Side A". I'm dry fitting "Top B" while "Side B" is just laying on the bench waiting for it's turn.
Mistake #2: I hadn't dry-fit the pieces before I started gluing. Now when dry-fitting "Top B" I find that it doesn't mate up against it's common edge with "Top A". Not even close.
With "Top A" already joined on one side my options on getting the two to mate as close as the Weld-On #3 required were limited. I used a new sanding station I just bought for this project but I could never get the two edges a tight as they needed to be.
But I had a backup plan. Considering ahead of time my skill level I had also ordered Weld-On #16. This was a thicker solvent cement with the ability to fill small gaps. It's not as thick as airplane glue but thicker than #3. Small warning. You don't squeeze it out of it's tube. It's thin enough that it just flows out.
That helps correct Mistake #2 but now I'm bitten by Mistake #1. When I was doing all the edge sanding on both Top pieces I should have clamped them together and sanded them as one piece. These two pieces started out the same size but with varying amounts of edge sanding they are now a different width. This becomes obvious when I dry fit "Side B" onto the edges of the two Top pieces. So back to the sanding board. I lucked out in the fact that "Top B" was wider so it was the one that needed sanded down. If it had been "Top A" that would have been a real hassle.
Get all my mistakes corrected and clamped together for more gluing.
Beside the squeeze bottle, a hypodermic needle comes in handy for applying the Weld-on #3. I don't know if all hypodermic needles are made from the same material but the one's I had laying around didn't react with the Weld-on #3 and worked fine.
Final step was to glue on the end pieces then do a test fit onto the top of the battery box.
Looks and fits OK.
Now to test it. I'll substitute a water-tight test for an air-tight test. I'll admit to wussing out at this point. If it failed the water test I'd have to wait till it dried out before I could fix it so I just went ahead and reinforced all seams with the Weld-on #16. Even the one's I thought I got just perfect.
Since the Weld-on #16 is runny I would tilt the box so that whatever seam I was treating would be the lowest point. After an hour the Weld-on #16 would set-up and I'd move to a different seam.
After all seams have set-up, fill with water.
Success! Not a single leak.
continued -
* This post was
edited 03/18/10 01:30pm by WVvan *
Open the pod bay doors Hal.
Once I exit Hal, this is what I do.
WWW.WVBIKE.ORG
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WVvan
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Acrylic lid continued:
Supplies:
Lowes
nylon hose barb splicer - 5/8" x 5/8" - $1.41
Loctite Plastic Bonder - 20 Min -.85 Oz - $5.72
The battery box lid has been assembled and water tested.
Now add vent hose fitting.
Here are an assortment of parts for the venting system. Most of these I'll be using later. For the lid I'm using one of the 5/8" x 5/8" hose barbs.
Only need half of the fitting. Used a hacksaw to cut it.The fitting had a ring around the center to separate the two hoses that normally would have been attached. Cut it so all of that ring is on one half. I'll use that half and call the ring the base.
Need to find the diameter at the base.
Closer to 11/16" than 5/8"
Will use a 3/4" spade drill bit. Figure out the hole location. Ultra fine Sharpe works really well for marking on the acrylic. Cleans off with alcohol.
Choose the location just below where the two Top acrylic panels meet. This is the highest point so hydrogen gas will collect here.
Supported the lid from underneath with a piece of 2x4 to reduce the chance of cracking it as I drilled.
Maybe not dead center, but close enough.
Do a test fit of the hose barb. The barb is pushed through the hole from inside the lid. The barb base is up against the lid on the inside. Looks OK.
Here is what I'll be using to attach the hose barb to the lid. I've read that the if you use a slower setting epoxy the joints will be less brittle. That's why I'm using a 20 minute epoxy versus the 5 minute kind. Instructions recommend roughing up the acrylic with 220 grit sandpaper first, which I did.
Mix up the epoxy and apply liberally.
The connection between the acrylic lid and the hose barb has to be air tight. I used clamps with a piece of scrap wood to hold the base of the barb tight against the side of the acrylic lid. I put a piece of plastic shopping bag between the epoxy and the wood so the wood wouldn't also get stuck. I figured I could always just pick off pieces of the bag after it set up.
Let it sit more than 20 minutes. Then when I went to take off the clamps I found that the shopping bag hadn't stuck at all. It just fell right off. So either shopping bags don't stick to this epoxy or it had skinned over before I put the bag against it.
Looks OK. Let it sit overnight before I stressed it. No problems.
continued -
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RVSKIER
Seattle, WA
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Joined: 04/23/2004
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not to be a kill joy or anything but are you sure that vent hose is big enough?
When I installed a vented battery box the vent hose was about 1.5 inches in diameter.
RVSKIER
2001 Itasca 30W
Faster, Faster, Until the Thrill
of Speed Over Comes The Fear Of Death
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WVvan
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Quote:not to be a kill joy or anything
All questions cheerfully answered.
I'm planning on having a small exhaust fan. Which means I haven't built it yet but it's on the list.
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WVvan
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Acrylic Lid continued:
Before adding hold-down straps I'm going to beef up the lid with some more supports. None of these might be needed but since this is my first work with acrylic I'll err on the side of caution.
Add an extra panel on each end. Since this panel fits flat against the panel next to it no need for the tedious edge sanding.
Mistake Number 1. When I first went to glue these together I used the squeeze bottle to cover the new panel with Weld-On #3 then leisurely held the panel against the lid to join them. WRONG.
Live and learn. From when the Weld-On #3 first hits the acrylic you have about two seconds to finish applying the glue and get the two pieces together. Not nearly enough time for a piece this big. No permanent harm. Clamp together the two pieces then use the capillary action method for applying the cement.
Did both ends.
Then add a brace across the middle of the lid at the location of the hose barb. Had to notch the end of the brace so it would fit over the end of the barb. In this picture the lid is upside-down. The brace doesn't go all the way to the top of the lid as so not to obstruct the airflow. Used tedious edge sanding on the brace before cementing.
The hold-down strap will be made from a bungee cord I had hanging around. Need to find it's diameter. It's close to 1/4 ".
So if its .25" and the acrylic is .2" thick then four pieces stacked together should give me a good base. Cut out the needed acrylic pieces from some scrap.
Glue together 2 pieces at a time. Since the pieces are so small the "apply Weld-On #3 on one side then slap the two pieces together" technique worked OK. The problem is that once the two pieces touch each other you have about an instant to get them properly aligned.
Next join two sets of two. Because of the quick setting nature of the cement I didn't get the blocks as even as I'd like. Here I'm about to sand a block to even the edges. This is just for looks. I'll be gluing it to the lid using the flat side, not the edge
Drill a hole through the middle for the bungee cord.
WARNING: As the drill bit exited the other side it grabbed the block and caused it to spin. This is apt to happen when drilling harder materials. I thought I had a good grip but not good enough. It spun around and gave me a right little knock on the fingers. Luckily No damage.
Cut bungee cord in two. Feed one cord through the block. Add a washer for extra support.
Fold over the top of the cord. Use three 4" cable ties to squeeze and hold closed the fold. Needle nose pliers work well at cinching up a small cable tie. Clip off excess tie ends. Do the same for other block.
Glue block to end of lid. One each end.
Add a screw hook to the base block. I've glued the bungee blocks an inch off center so the hooks won't be in the way of the bolt that should go through the center of the base block to secure the battery box to the van floor. The screw hook is where the bungee cord attaches to keep the lid shut.
Take the base outside and give it a couple coats of paint.
All done.
In this picture you can see Quality Control Engineer Bob checking where the lid meets the base to see if the closing tolerances are within agreed upon specifications. Either that or she smells fish.
Without the batteries weighted the box and lid with a bathroom scale.
And one battery.
23 + (4 x 64) = 279 pounds of house batteries.
Consider this the finish of the Battery Box build.
Next up is the sofa-bed build.
Here is a scale drawing of a small part of it.
The thing at the bottom is NOT a hand grenade but if I keep having as much trouble as the sofa-bed build is giving me it might get blown-up before it gets finished. Blown-up real good.
* This post was
edited 03/24/10 06:20pm by WVvan *
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doughboy81972
Delavan, Wi.
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wait Bob is a she wow I thought that naming my cat Miss Kitty was weird
also the box looks good there is a way to get rid of the white scuffed edges on the lid by using a torch to "flame polish" the edges I have done it before and you have to keep the flame away and keep it moving so it doesn't bubble the plastic
Steven 35
1 dog
IL Rallies attended 
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WVvan
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Hey Steven,
Thanks for the tip. Is the flame polishing just for looks or can you also use it instead of the "tedious edge sanding" before edge gluing?
And as for Bob, well she must like the name because she always comes when I call.
OK, sometimes she comes when I call. OK, she'll sometimes turn her head in my direction.
OK, she totally ignores me unless I open a can of tuna while calling her name. Then she comes running!
Yes sir re bub. She's a Bob.
Dave
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doughboy81972
Delavan, Wi.
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no you still have to sand to get the glue to stick I am just talking about the edges that are exposed
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WVvan
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Gothca ya'. Thanks.
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WVvan
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A little housekeeping.
Once I saw this photo of the inside of my garage door I knew I needed to do a little housekeeping once the weather warmed up.
So today's work was some much needed painting.
While I had the paint out I noticed the work table could use a touch-up.
Never looked better.
PS.
Just now.
Final: West Virginia 73, Kentucky 66
We haven't been in the Final Four since Jerry West took us there in 1959.
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