Two new obsessions

[brian and clare]

Damn, sombody already invented the thing I invented. First the hydraulically assisted pogo stick, and now this! Im deadly jealous. Do you have to assembe it yourself then? Two words: Neat-o!

[knottybuoyz]

When they tell you that all foams (for core) are not created equal you better listen. I cut the parts to fit the pump and outlet. Here's what I found.



The part looks ok. There looks to be a really good resin to glass ratio. No voids. Then on the second part this is what happened with the jig saw.



The foam was completely bonded to the glass/epoxy. The foam itself failed. I'm guessing that's what they mean when they look at the various factors, sheer modulus, etc. when they describe foam qualities.

The infusion epoxy is still a bit soft (stretchy) but is getting harder all the time. Mfgr said up to 2 weeks before it's fully hardened. You can post-cure (heat it up) to expedite the curing process. I might try that next time because this epoxy has an extremely long working time (+5 hrs) and +24 hrs to demolding the part.

The 1708 glass/epoxy ended up almost exactly 1/32 of an inch thick! Somehow I thought it would have been thicker but due to the vacuum clamping it's been compressed quite substantially.

[knottybuoyz]

This is what happens when your resin trap is "Waaaaaaay" too small!



This is the new one. Hopefully I won't be filling it up anytime soon. It is 100% PVC and the epoxy doesn't stick to it. There is a clean-out on the bottom. It acts as a vacuum reservoir as well which is what the black pipe in the upper left is. I figure I'd have to ingest two gallons of epoxy into both of these before it could ever get near the vacuum pump.



Yet another lesson learned! Makes for some nice "epoxy art" though.

[DeepFrz]

Rick, the foam made for infusion normally has holes drilled through it so the resin can penetrate. Now if you were only doing one side at a time you wouldn't want the stuff with holes. The holes help the resin spread evenly.

Great lesson learned on what type of foam not to use.

What are you going to use the parts for?

To bad you hadn't suspended a fly in that resin...<gr>

[knottybuoyz]

Originally Posted by DeepFrz

Rick, the foam made for infusion normally has holes drilled through it so the resin can penetrate. Now if you were only doing one side at a time you wouldn't want the stuff with holes. The holes help the resin spread evenly.

Great lesson learned on what type of foam not to use.

What are you going to use the parts for?

To bad you hadn't suspended a fly in that resin...<gr>

Heya Frz

The biaxial fabrics flow the resin really well. I also had the flow media (plastic mesh) on the bottom as well. It wicks the resin along the bottom of the part just as easily as the top. I thought that all that pressure on the part the bottom would be starved for resin but it wasn't. It's actually pretty amazing how powerful the vacuum is at pulling the resin through the fiberglass.

I've seen the foams with the holes and they make scored foams as well. The scored foams are used when you're making parts that need to bend to conform to a curve.

I was just tinkering and decided to make a cover for my sump pump hole! *lol* that's why I used the cheap foam. It's not a critical part.

Yeah, flies, lures, baby teeth etc. *lol* Maybe a new sideline "Ricky's Epoxy Art". I'll make a fortune on e-Bay! They do make clear casting resins for that stuff!

[knottybuoyz]

Attempted the second infusion today. Failure and success.

Success: Got a perfect bag. Had to chase some leaks with gorilla snot and acoustical sealant but managed. I picked up a couple of "Spy Ears" off of e-Bay. They're kids toys that magnify sounds so kids can play spy stuff I guess but ya know? they worked great! For $2 plus shipping I thought I'd give 'em a try. E-Bay item #120149832296

Failure: The stupid semi-circle is a nightmare to infuse. I thought I was being smart setting up the perimeter vacuum and infusing the resin from a central point. Well sh*t! The epoxy immediately ran around the part to the vacuum outlet! As you can see from the pics it followed the minor bridging along the edges. This left a huge void in the part.

Success: We fell into Plan "B" after a half hour when it became apparent the remainder of the part wasn't going to infuse. We clamped off the resin feed and relocated it to the center of the void. This was easier than I thought it would be and it worked. After the void was about 80% complete we sealed off the inlet and let the vacuum take over. I don't know if there's a void on the bottom but I'm assuming there is. That'd be cool then I can try a mini-infusion on the void there like you'd do on a repair.

Success: I used only a small semi-circle of flow media, enough to get the resin up and under the part. That worked well and the biaxial fabric flowed just fine on it's own. I also provided a resin break of just peel ply between the part and the vacuum outlet which is probably the only thing that saved our bacon this time. We used about half the resin we did last time and I don't think there's more than an ounce or two in the resin trap.

No more semi-circles for me! I don't know enough yet about how the epoxy flows through the stack. Well I know more than I did two weeks ago! I'll demold the part tomorrow and we'll see how we did.

[knottybuoyz]

It popped out slick as sh...........

Well. The toughtest part was getting the butyl tape off the mold. That Polymer Composites mold release wax works extremely well. Better than the stuff I had for the first test.

Note to self: Flow Media goes "Over Top" of the peelply! Don't let me forget that!
The flow media is now a permanent part of this part. Good thing it's not a critical part for a paying customer. Guess I was in a bit of a rush to get the job done. Anyhow, the part is still serviceable for the intended purpose.

With no peelply on the bottom the part is smooth as glass! The downside is without the flow media the part was starved in a kidney shaped pattern. I sort of expected that. That'll provide an opportunity to do a "spot infusion".

I'll have the cut outs tomorrow so we can see the and measure the thickness of the glass/epoxy.

Better than the first but still not perfect. Good thing I only have 1 sump hole to cover! No more semi-circles!

Now all I have to do is learn how to use a HVLP paint gun!

[DeepFrz]

You probably have this document but just in case you don't here is the link.

http://www.fibreglast.com/documents/361.pdf

Your sump cover is looking better all the time. What's the cost so far?

[knottybuoyz]

Originally Posted by DeepFrz

You probably have this document but just in case you don't here is the link.

Thnx Frz. I have read that one before.

Originally Posted by DeepFrz

Your sump cover is looking better all the time. What's the cost so far?

I don't know! Might have to ask KnottyGirlz if she's seen her Mastercard statement yet!

Just in those two parts, hmmmm? probably $50 worth of materials. Like I said before it's a wasteful process with all the consumables. There were a few misques that cost a little bit like too much resin on the first run etc.

I'd say including the vacuum pump, plumbing, tubing, fittings, butyl tape, peelply, bagging film, flow media, wax, PVA etc. another $400 - $500 in stuff to make it all come together. A lot of which I still have for future projects.

Probably the most expensive sump pump cover in history and I'm not finished with them yet. Going to paint them next with the new HVLP sprayers! (which I don't have a clue how to use yet). Anybody for a metalflake sump cover? Flames maybe?

[knottybuoyz]

Well so the next chapter in this saga has played out. I tried to do a spot infusion of the void in the part. Yeah ok.....

The fresh f/g part was porous and it was near impossible to hold a vacuum on it. The pumps still runnin'. The resin moved well through the part with the peelply and infusion media in the correct order. The resin flowed really well till about half way then it started to race along the creases in the bag and along the very edge of the flow media. Sheez. I stole a trick of making up little diapers of bleeder to suck up the excess. No resin in the vacuum line this time.

We'll see how it turns out tomorrow.

Do you know what to do with excess epoxy when you've mixed up too much? I do!

Knock the cup off of the table and coat the floor with it!

[knottybuoyz]

I learned a couple other interesting lil' tidbits about epoxy today.

1. You can't comb partially catalyzed epoxy from your hair
2. Make sure you wipe up all the spilled epoxy before you put your tools back down in it
3. Don't just cover the spot where the epoxy spilled with a chunk of old carpet
4. Advise the Admiral where you spilled the epoxy so she doesn't walk through it!
5. Check the back of your hands for uncured epoxy before you wipe your forehead with them!

Oh this is fun!

[knottybuoyz]

Oh I'll learn eventually. You only gotta hit me over the five or six times before I figure it out!

I also learned no more grinding fiberglass in the basement. *scratch* *scratch* *scratch*

Well not finished yet. Once I get these HVLP sprayers figured out and tuned I'll paint them. Also going to dowel them together so they'll stay put. That should keep the cat toys and tools out of the sump!



The panels are incredibly strong but I still wouldn't advocate using that cheap blue foam in a boat. I stood with one foot on each and they never budged and I'm no lightweight at 240lbs. Probably the most expensive sump cover ever made!

[Whimsical]

Originally Posted by knottybuoyz

I learned a couple other interesting lil' tidbits about epoxy today.

1. You can't comb partially catalyzed epoxy from your hair
2. Make sure you wipe up all the spilled epoxy before you put your tools back down in it
3. Don't just cover the spot where the epoxy spilled with a chunk of old carpet
4. Advise the Admiral where you spilled the epoxy so she doesn't walk through it!
5. Check the back of your hands for uncured epoxy before you wipe your forehead with them!

Oh this is fun!

Good to see you are getting stuck into it.
Point 1- Yes you can , I do it all the time. Finally learnt and now wear a shower cap when working overhead. Vinegar is great for breaking it up.
Got some in my eye, stung for about 2 hours, so now have some goggles.

Mike

[Ex-Calif]

Rick - I love the way you are taking knocks at yourself as you learn this and for sharing your mistakes - the only way to learn and maybe we can learn from some of your hiccups.

Keep 'em coming

[knottybuoyz]

Originally Posted by Ex-Calif

Rick - I love the way you are taking knocks at yourself as you learn this and for sharing your mistakes - the only way to learn and maybe we can learn from some of your hiccups.

Keep 'em coming

Thnx Dan

My ole' grandpappy (God rest his soul) used to have a saying that went something like this: "If you can't (or don't) laugh at your own mistakes then you don't have any right to laugh at someone elses." Something like that.

Yet another skill to refine before we risk a couple grand in materials on the hull of our boat. Still a lot to learn. Trying to figure out what I can make next.