Tim's new project

[TimT]

"Sloth Barney " Me thinks our friend Stewart is playing little tricks on me. I'm not upset because I know how much rust came pouring out of his head set....It was a very clean and pretty bike.....and the tire label lined up so prettily with the valve stem.

Any how ....Got the frames back from powder and boy do I love my buddy Jaxon. You see he took pity on me and coated my frame in the most beautiful gloss black you have ever seen.

He did coat the 2nd child's of mine frame in the purple.

She's going to be very excited. We will paint the fork later and we will put some pink and purple parts on it. But for now it will be a rider. While I was there we played with the left over purple and mixed in some black a baked it. Kind of a weird spotty thing.kind or reminds me of metal flake. I have a road frame going together and as soon as its done he'll coat it with that mix and maybe add some silver. For now I'm going to finish a bathroom, the kids bike and somebody's Titus......... Then I'm going to work on fixing the popping noise coming from the belt drive. For that I'm going to get all mad scientist. Just waiting on some stuff in and I'll start the experiments. So basically the plan is to stiffen the chain stay with some expandable urethane foam.

Its sort of like the spray insulation foam you get at Home Despot. But on steroids. The foam in the can is .5lbs (notice the point in front of the 5) this stuff is 16lbs. You can hit it with a hammer and it won't dent. Trick is getting it in the stay. So I will experiment on some scrap tubes and hopefully get it to work. If not its tensioner time.

later
Tim

[Monkey Boy]

Is it the same foam bike manu's use? I always wondered why foam a tube vs. using different wall thickness for rigidity?

They used this expandable foam that hardens like concrete to lift my foundation during the drought last summer. No mechanical devices, just 5/8" holes every 6 feet to pump the stuff in. Lifted the 2 story section of the back half of my house almost 4 inches! They barely even moved any furniture, just pulled back the carpet, poked a few holes, pumped in some foam, and were in/out in 4 hours.

[TimT]

Not sure Brian the only foam I know of in use for cycling is styrafoam. Some companies use it as a core material for carbon fibre parts. Never even heard of using foam to lift a house. I've seen the cable lock system and the 8 inch concrete blocks and the hydrolic ram method but not foam.I'd like to see that.

Tim

[Monkey Boy]

Process has been around for a while in Europe, mostly on roads. Here's their website that sort of explains it all. www.uretekicr.com

It was 1/3 the costs of traditional 15-20 holes in the slap, jacking it up & using I-beams. It didn't destroy my flooring, didn't have to relocate for 2-3 weeks, only took a few hours, and didn't involve packing up our whole house & paying storage. Even if it only lasts a few years I'm way ahead in $$$ & PITA.

[TimT]

So went to the "lab" today. So the first thing I did was mark half of the stuff I was using to draw out the chemicals and mix with I did this with some blue painters tape.

I did this so that I wouldn't accidentally harden anything. Next I loaded up a special double syringe. I got it from McMaster Carr. They come in 5 packs and are used to mix epoxy's. I also got a special mixing needle. Now I did e-mail the people at US Composites and they didn't have much luck with this method as it depends on mixing thoroughly , so if the needle sucks then its no joy. They were very helpful and shipped very quickly and responded to my e-mails right away. I will do business with them again.

I mixed 5ml. of each and squirted it in a cup.

No joy. It sort of sat there. I waited 2 minutes. Its suppose to start to harden in 45 seconds. Nothing, so I mixed it up with a stick. Sure enough in about 45 seconds it started to foam a bit and harden up. So then I got another cup and put 5 more mls. into it and stirred it up. Holy crap in 45 seconds it foamed up to about twice the size and man did it get hard!

So I waited about 20 minutes to let everything settle down got a hammer out and whacked the crap out of it. So the one on the far left is a bit of the foam you get out of a can from Home Despot. You can smash it flat with your fingers. Wow big deal. The one in the middle was the first try with the mixing needle. It left a mark on it and a small dent. The one on the far right is the one I mixed by following the instructions. Imagine that it worked as advertised. No dent no mark nothing. The wife came out and rolled her eyes at me as I whacked it and smacked it. So now I have a problem. I have to mix this stuff for 20 seconds (just like the dude told me to) and then pour it into a chain stay. 25 seconds oh boy. So back to McMaster Carr. They have some big syringes. The new plan is to get a couple of big ones and mix in the syringe and then inject into the stay. So while I wait for UPS to show up with my stuff. I'll prep the frame. I'll try to do this in the next couple of days.

Tim

[TimT]

OK went back out to the lab and with my lovely wife taking pictures (thanks hun) and did some more experimenting. First I wanted see if I could mix in a syringe and get it in a tube fast enough. Second I wanted to see how much it expanded and if the expansion would burst any tubes. So I found a clear plastic tube at work. For the record its about 1/2" ID with a .012" wall. Very thin. Some welding wire came in it and it was empty. So I decided to save it from the trash.

First I put 10mL of water in the tube and marked it with some tape. The top of the tape is the mark. Next I plunged the syringe with a nail so the stuff wouldn't leak out as I was mixing. Then 5mL of part A in the syringe then 5mL of part B. I mixed for 20 Mississippi (seconds) with a piece of welding rod. Then I squirted it in the tube.

After about 25 seconds it started to expand up the tube.

After a couple of minutes it stopped and sure enough just like the guy told me and the printing on the can it expanded to about 4X its volume.Then I let it sit for 30 minutes. The tube got hot. Just warm to the touch not to bad.

Before I could crush the tube with my fingers.

After hard as a rock . I tried to squeeze the tube flat but no way no how. I can still bend the tube some. but not like I could before I put the foam in.
So What I learned.
1. this stuff is bad a$$
2. It won't blow up my tubes or my face.
3. I can work fast enough to get it were I need it.
4. dude was not lying about what to do and how this stuff works. I like that.
Question still
1. I can still bend the tube so will it stiffen the stay up enough?
Plan of attack. Fill 10mL of foam through the BB hole, tape off and tip frame up. Let it harden for a couple of hours. Measure were the foam stopped with a rod through the hole by the drop out. Figure out by guestamite how much more is needed. Inject another ??mL of foam through the hole at the drop out.
So now I wait for Brown Santa for the other syringes from McMaster to come in. Tomorrow a buddy's coming over and I'm working on his bike and Friday I'm cutting grass. I should have some time on Saturday after my ride at the Spillway. Hopefully everything will be in place by then.

Tim

[TimT]

Ok decided to do one more test. I wanted to see if I could "stuff" more foam in the tube. I figure the more the stiffer Right?? So I took a piece of 1/2 copper pipe and cut it about half the length of the plastic one and capped off both ends. I drilled a hole in one of the caps.

Next I mixed up 10mL of foam and injected it in the pipe bomb.

It pretty much came out the top. Pretty messy so I wrapped it in some paper towels.

Not really sure if any extra got left in the tube. But learned a couple of things. One I can fill in one shot and not worry about over filling and busting the stay as long as I have a vent hole. Second this stuff is a sticky mess I'm going to have to tape off the bike. So next I filled the stay up with water.

I have a volume of 128mL. The syringe will hold 35mL which will expand to about 140mL. So I did some dry runs and figured I'd fill from the BB and put a rubber plug in the vent hole. Its about 1/4 inch. Then tip the bike and vent from the drop out. With enough tape and news paper I'm golden.The dry runs were awesome. BUT in reality..... So the camera ran out of battery power. Sorry no pics of the carnage. But I mixed up 35 mL and injected the stay went to put the plug in and the sucker wouldn't go.WTF worked in the dry runs. Like clock work 25 seconds later the foam began to expand.So like a Dutch Boy I stuck my finger in the hole and tipped the frame. SOB. this sucked. Grabbed a handful of paper towels with the other hand and stuffed them in the BB. Lost some out the BB not much and then it started to come out the weep hole at the drop out. Great the stay filled up. I have it coming out of both ends. So then I waited 5 minutes and removed the tape and news paper. The stay was warm to the touch. Got some mess around the BB area but the tape and news paper payed off.
I took a razor blade and trimmed the foam at the holes. Got some spill on the bottom side of the BB so no big deal.

So now I'm back to assembly. I did get a sticker pack for the bike but I kind of like it bare. I did put one XXiX sticker on it. I also decided to put a strait post on the bike for a bit better fit and I'm making some small bits. So I might finish this bike in a week or so just depends on when the post gets here.

later
Tim

[stu]

I did get a sticker pack for the bike but I kind of like it bare.

Once you go black, you never go back.