It’s too bad they don’t teach this stuff in high school; no idea where one can get a hands-in education in vacuum lamination techniques. Things are being done safely here in the shop thanks to book and video study. But it’s all the little tricks not known that cause extra time and sometimes rework (go back a few posts to the vacuum pump saga :)
This week I think we’ve finally gotten in the groove, so in case anyone reading this stuff is just starting out, maybe these musings can help reduce some error in your trials?

That’s the second of four stages vacuum laminating the net lashing tubes to the hull’s port side. Significant only because it’s the first success using a splitter to draw vacuum on two separate projects in one pump run. A small moral victory around here.

Stage 3 was the 15 foot section between the main beams. Here are the steps.
Took measurements between the temporary straps, and cut all materials to leave an inch and a half on both sides of the straps so epoxy wouldn’t migrate over the straps.
Built the bag down on the 8′ work table where it can be stretched snugly and the sticky goo tape applied, leaving the paper backing in place. Setting up the tape in this calm manner, before any epoxy is mixed, took me too long to realize!
Planned for add-on patches to make out-of-the-way zones in the bag for the pump fittings to sit. Leaving at least six inches between the air connection and any live epoxy work, linked by plenty of breather fabric, keeps the glue away from the pump’s tubes and fittings. (Learned after a nasty hour of scraping out glue-fouled bag fittings one night – these parts aren’t a quick Home Depot replacement).
After cutting fglass fabric to the six inch width for this job, the ‘bagging’ supplies were cut: peel ply at 7 inches because a bit of overlap makes it MUCH easier to remove later, release film at 6″ because any more would be waste, breather fluff at 5.5″ because when it goes all the way to the edges it invariably ends up adhered where you don’t want it, like on the hull!, and the bag film itself at 11″ – leaving 2-3″ past the edge of fiberglass is minimum. For this vertical work I needed the bag to help hold the wet materials in place before the pump turned on, so I cut it close and snug on purpose.
With materials all ready, it was time to apply the putty fillet around the pipe, and let it harden up a bit, but still pliable for the bag to press the fiberglass into the fillet and be able to take by-hand smoothing from the outside of the vac bag.

Here’s the bag in place, but folded down out of the way.

Then the fglass was wetted out on the table and rolled up like little pillsbury crescent rolls (sans hot dogs, Mom) and walked over to the boat after sitting under warming lights for about 20 mins to get tacky (sticky). Here that is with peel ply to help hold it up. Note that it won’t adhere yet to the underside – gravity wins.

The heat lamps are going because there is a putty fillet above and below the pipe, trying to time it so that is just hardening when the vacuum is applied. Too early and it will squish out; too late and there will be ugly lumps in your cream of wheat.
Next shot is after applying release film and breather fluff, some of which needed dabs of masking tape to hold in place. Bag was then brought up over the work taking care to tuck things in flatly.

With this long, complicated bag, there were some air leaks but they were solved in a few minutes by pressing the tape all over again and adding a few inches of backup here and there. Having these separated tube attachment areas has helped quite a bit, compared to earlier work where I didn’t plan out the connection spots. Cut the bag to fit the work, and simply add a big ‘patch’ as needed.

All in all, no drama today and it all came out with nice, uniform tubes that need only minor fairing work. In retrospect, I probably did this all backwards; someone could try small 2-3″ fiberglass strips next to the pipe straps first. Then remove the straps after the glass strips dry, and you could probably do the whole project in fewer bagging sessions. Just a thought.

And as Jeanne’s Mom always said when preparing the fruit for canning, “I found the one we’re looking for – the last one”…. Here’s beam number four escaping the oven. Don’t ask about the electric bill. This big box is REALLY in the way, but it will stay up another day or so to bake the rudder after the last fairing work. Getting excited to start on the rudder’s cassette steering assembly!

It’s actually hard to find a remote-sensing thermometer that will read warmer than your average bad day in Death Valley. This one from Home Depot tops out at 158 degrees, which works for our 160 target. The ‘oven’ has a removable section of Sheetrock to reach the power switch and read the old fashioned meat-cooking thermo inside to make sure we don’t get a runaway thermal event past 175 degrees or so. This combination does the trick. We also had to hard-wire some temporary plugs, conduit and switches because regular power strips couldn’t take the heat or current draw. Also needed to find a replacement air circulation fan after smashing Colin’s nice little unit with a little slip – oops. The fan is a must with a box this big – think of how convection ovens have hit the home improvement market.
Too many trips to the hardware store and wasted time on various improvements, but this post-curing system is now a-ok. Beam #2 was cured on Sunday, and the other two will fire early this week.

Meanwhile, the net lashing anchors are going on the main hull, similar to how it was done on the beams. Step 1 was temporary strapping of the PVC to the boat – it makes a nice clean line all along the gunwale …

We’ll laminate the fiberglass in sections, skipping the spots where the pipe straps sit. Once the primary bagging is done, we can hand-patch the little spots left in between. The straps are held with tiny 1/2″ screws, in just enough to bite. Those little holes will get putty filled before we proceed to seal everything up.

Sunday afternoon was spent preparing the 186′ of six-inch wide 18oz fglass fabric needed to create these lashing anchors. That’s 31′ along the hull x three layers x port/starboard, plus all the vac bagging materials. After ten minutes of scissor-burning wrist work, it was a run back home to grab Jeanne’s fabric cutting board and rotary cutting wheel. That helped a bunch, and it was returned in time for tomorrow’s prom dress sewing.

Rudder fairing is good – first side finished today, and we attempt to get the exact match with side two starting tomorrow. Just keeping things fair, man!