RickK's 170 rebuild

[RickK]

This is just a test to see if it will even work, so no peel ply or breather yet. Cut the top layer and remembered that I needed to leave it loose (6 mil is still pretty thick to manipulate - could only imagine working with 20 or 30 mil).  Cut the stem (frog) hole, added some 1808 folded as a mop under the stem. Taped it down


Let it rip

[RickK]

Learned that I didn't leave the upper sheet loose enough but it did work.


Not great vacuum but not bad so it probably means I have some leaks on my tape - could hear a little air hiss but the compressor was too close to hear well. I lifted the top layer and moved all the tape inward about 1/2" and tried my hand at pleats and let it rip again. It pulled it down around the edges a little better this time so I guess I still need some more slack in the bag.  I'm waiting to do the real thing until I get my tape - should be here today.  Will probably start with a little bigger area on the floor too.

[wingtime]

COOL!

[CLM65]

Man, so far I have been resisting the vacuum bug that you and Carl are spreading...but I don't know how long I can hold out.  That does look cool!

[Callyb]

Rick, if you are only pulling 15" max you definitely have leaks to contend with. It really didn't take much of a leak to make my 3cfm half useless. Also, since you are using the heavier plastic you can hit it with a heat gun while it is under vacuum to eliminate the bridging, basically heat forming the plastic drop cloth.

I'm excited to see what you come up with.

You will be impressed with the lamination once you pull it too!

[RickK]

Right after I posted the initial trials Santa showed up and dropped off what I needed to do the real deal.
Sticky tape - man this stuff is incredibly tough.  Once it's it's pressed or vacuumed onto something it's toast - you can barely pull it off the plastic, plastic gives first  


Peel ply and the real bagging material - thought I was doing ok with 6 mil - the real stuff is only 2 mil. The white stuff is the wick or "bleeder" layer of the lam.

[RickK]

This is what the roll goods look like - the perforated peel ply is the blue, the 2mil bagging material is the green stuff (110" wide per yard)


Also picked up one of these - the console will be the first experiment - soon.

[seabob4]

Rick, I was a supervisor in the Non-Metallics center at Lockheed-Martin, we did a TON of vacuum bagging on missile parts, heat shields, filament heaters, you name it.  You want good materials, you need EXCELLENT sealing tape (looks like you got that!) if you want to pull 30" of Hg.  Those wrinkles you see in your bag at 15"?  They'll pucker tighter than your butt does when a steering cable breaks at 30"...

[RickK]

We (Ed and I) tried out the new tape and how much pleat to use (that's when I found out you ain't reusing this tape again or anything it's attached to) and I went through 1/2 the first roll just in practice.  
What did I learn:
1) The visqueen on the garage floor works great as a platform for airtightness (word?).
2) You need to apply the tape to the bagging material, NOT to the visqueen.
3) You WILL need to "pleat" the bag so you have to experiment to learn how to do that at the expense of tape and plastic (and duct tape)
4) We figured out that you need to cut the bagging material 6" inches larger (3" on each side) than you need it all around and apply the tape without much pressure or much pulling.
5) With the bagging material laying over the target material (with the tape already applied to it - protective tape (PC) still on one side) mark the visqueen taped to the floor 1 1/2" inside the edge of the tape all around.  This will be where you stick the tape down, which will cause you to "pleat" the tape and bag - see pics.
6) Cut a 1/4" X in the desired corner for the stem to penetrate the plastic. Install the stem.  
7) Starting at the side with the stem, peel back the PC at just the corners and lightly press the tape in the corners where your lines intersect - both corners on that line.
8  ) Holding up the center of the tape, peel back the PC from this side and working from both corners lightly smooth/press the tape onto the plastic and in the middle you'll have some excess that you'll make into a pleat by squeezing the tape together and pressing the joint down onto the plastic so it makes a good seal.
9) Lay back the bagging material over itself.  
10) Before you proceed make sure you cut the layers you need  for the bagging and don't cut them too large. Make sure they fit within your new lines.
11) I learned that I needed to cut the 1208 just long enough (or maybe just a strand shy of) to make it over the edge and to the bottom of the hatch. I initially thought that I would bring the cloth over the edge and let it run long, to trim later.  With the pressure I was able to pull (about 18), it pulled the cloth over the edge better to cut it short.
12) Have the cloth, peel ply and bleeder cloth ready and mix your resin (I am using poly) and cross your fingers and stay calm.
13) Coat the target and the edges well with resin, and then set/position the cloth, hard roll and roll more resin on top and edges, making sure the edges are wet enough.
14) Staying calm, apply the peel ply and bleeder layer of the bagging material to the target.
15) Pull the bagging material over the top and working (hopefully with more than yourself) the sides, line up the next corners and stick them and work the tape down and pinch the pleat.
16) Work the last edge the same way as the first and secure it to the plastic.
17) Connect the vacuum line to the stem and turn it on, low vacuum at first if you can.
18) As it pulls the plastic down use your hands to help the vacuum pull the top flat/smooth and the edges round and then turn the vacuum up to full blast.  Continue to help it pull the material around the corners.
19) Grab your camera and take a pic for your buds and then grab a beer.  I let the vacuum run for over an hour and the piece was still sticky when I pulled it.

[RickK]

Here is the layup - cloth, perforated peel ply and bleeder cloth


Following the instructions above - Oh boy, here we go, this time using the 2mil bagging material

[RickK]

I was able to get a pressure of 18, not ideal but adequate and we let it sit for an hour


Pulled the bag off (not easy) and the bleeder cloth and this is the hatch with the peel ply still on

[RickK]

Peeled back the peel ply and it was a wonderful result  


Look at them edges      - no way without some clamping mechanism will you get cloth to roll over an edge.  I used 1208, now I wish I would have gone with 1708  

[RickK]

Tank hatch tomorrow.

[fishinonthebrain]

Damn rick that looks good for the first time.

I just got my order of bagging supplies yesterday and will be trying it out in the weeks to come. I am going to try and push the envelop some though and do some resin infusion.

What are you going to try next?

[fishinonthebrain]

When you pull off the peel ply is it smooth or textured from the cloth? Is there going to be some faring to slick it out?