Mystere 6.0 refit project!

@charlescarlis

Hey Chuck.... thanks for the comment!

I read a post in a leather (belts, holsters, etc) sewing forum that indicated that the Organ brand of needles have a longer scarf area.... better for timing the rotary hook to the needle on the wide zig-zag setting. I had some good Schmetz needles and compared them, not any difference in scarf length that I could see. Anyway, I purchased Organ brand's Titanium regular point, ten needles per size from 16 - 22 (Singer sizing) in 16x95 (1738A) Needle System, from 'Cleaner's Supply' at what I thought was a ridiculously low price. Everything they sell is at least half price compared to everyone else's prices it seems. Got a bunch of spare bobbins and some feet, too. They didn't have the PTFE thread, though. They are pronto on the spot, too... received the goods in two days!

https://www.cleanersupply.com/tailoring-and-sewing-supplies/sewing-machine-supplies/sewing-needles-and-needle-threaders/organ-titanium-regular-point-industrial-machine-needles-dbx1-16x231-16x257-1738-10pack/#sku=mtnr16219

I purchased the 8oz spool of Aruvo PTFE tex 90 (Denier 1350) thread from 'Jukie Junkies' for half the price that everone else wanted! I didn't then know that the DBx1 needle system changes it's shaft diameters between size 18 to 19. The 'cool-running' Organ needles that I ordered here, of 19 and 23 didn't fit my machine, having 2.0mm shafts instead of 1.62mm. Doh!

https://jukijunkies.com/aruvo-tex-90-ptfe-thread-black/

Yeah, I rigged up a super-simple 'table' system using two saw-horses, 4'x3' piece of 3/4" plywood I use as an outside work table, and a big tarp (four layers) laid over everything including part of the sewing machine bench. Maybe not as a low coefficient of friction as those white plastic tables, but it works well enough, plus it makes perfect sloped transitions so that the tramp material doesn't hang up on any corners.

I took apart the ol' clutched motor and cleaned and slightly roughened-up the cork clutch pad with a small bronze welding brush and sanded/buffed the steel clutch plate. It works so much better now. Not quite like a good servo, but good enough for now. If I merely make the clutch-control linkage attach a bit closer to the pivot of the foot peddle, I think it will be just about right.

I'm getting much better at helping feed the tramp with the feed-dog cycling rates, as long as I keep the incoming tramp material positioned something like a wave coming into the beach, and help it a bit behind the machine. It keeps you on your toes.

What PTFE thread brand and what size did you use? I was thinking of going with tex 135 (Denier 2000) Aruvo (same price) but I was concerned that the smaller bobbins of my machine wouldn't hold much of that thread. Though, when I got the tex 90 Aruvo, I was surprised at how much thinner it is compared to what I have in bonded polyester tex 90 thread.

Woo Hoo!

Another installment of progress on the Mystere 6.0 ....

Hard, sticky, time-consuming labor will continue until moral improves!

So. Both hulls' centerboard pivot indent were eroded by many years of use, beach sand, abuse, whatever. 

Also, I'm guessing the method of molding the fiberglass centerboard well cases was by using a male mold with the forward edge a seam to pry the cured part (well case) apart to extract the male mold, then bond the forward parting edges together with bondo, gelcoat, and hopefully some fiberglass tape on the 'exterior' of the casing seam. 

That casing seam had a few cracks as well as bondo failure near the cases' bottom pivot indent. So out came the media-blaster. Nothing like blasting sand all over the place. But it's pretty good at abrading surfaces and loosening chunks of gelcoat that are not adhered well.

The above pixs show the forward casing seam of the port hull after blasting first with 'play sand' which kept on clogging the blasting gun, then with silicon carbide 80 grit which flowed out of the gun like a full-automatic's shower of lead. Oh yes! Don't go super-cheap on blasting media.

You can see a possible faux pas at the bottom of the seam (2nd pix)... it was pretty deep.

So for those not familiar with Tornado and Mystere centerboard casings, the slots on either side of the internal casing is a track for the centerboard pivot pin. At the bottom of the slot resides a close-fit pivot indent so that the pin doesn't wiggle around too much. The blue painters' tape on both pix above cover up part of the pin track so that I didn't booger-up those tracks with epoxy goop. It's a bit tight in there as maneuvering room goes.

The above pix: after painting and smoothing first some neat epoxy, then thickened epoxy (high density filler), I layed-up three layers of 4 oz. crow's foot (4-harness) 'glass on the laminating table, then gingerly slid the assembly down the case seam. Then used a small paint brush taped on an extension (scrap piece of thin wood) to smooth everything down. 

In the lamination process, I had a piece of plastic sheeting on the table with markings on it showing the width and length that the laminates where to be. Then whetted out each layer of 'glass on top of the sheeting, then added a top piece of clear plastic sheeting. Cut the whole sandwich with a sharp razor blade. Removed the bottom plastic sheeting, then applied the whole mess with a long,thin stick that I had taped the 'bottom' of the wet, goopy sandwich too. Slid the sandwich-stick down the case, aligned the sandwich to the seam, smoothed it all out with the extended paint brush, and BAM!! Done. After cure, the top sheeting came off easier than the blue tape did.

So the next job was to re-form the pivot pin indents at the bottom of the tracks. Both sides of the cases, both hulls. They were chewed up pretty badly.

I got ahead of my camera and ground out the left side of the pivot indent (right side in bottom pix) with a long-shaft pneumatic grinder with a carbide bit. Chased plenty of gelcoat/bondo cracks.

Above.... you can't get much more inexpensive and useful tools compared to the ol' Harbor Freight air tools. The air-valves on them are a little less accurate than a more expensive brand, but keep 'em oiled and they do just fine.

The next vid exemplifies the process of re-forming those pivot indents. Everything came out like I was envisioning. Yay.

Next, I want to make the centerboard slots on the bottom of the hull a bit tighter fit to the centerboards to the centerboards from knocking around and increasing their angle of incidence in relation to the hulls' centerlines, in effect reducing their angle of attack to oncoming water flow.

Gotta keep in mind that I also have to provide indents to the hulls' surface surrounding the centerboard slot so that I can add centerboard gaskets.

And no.... the trampoline re-stitching is not complete.

I tend to go bouncing around the workload just to keep my interest peaked. Though, I hate grinding gelcoat/'glass especially in this HOT weather. That's my next task.

Nasty.

Alright! It's hot Hot HOT outside, so I'm taking a bit of a break in the air conditioned comfort, just to provide you guys and gals with a little update on the Mystere refit....what a guy! 🤣 

After re-molding the centerboards' pivot pin indents, I noticed (duh!) that there was a good bit of lateral slop between the centerboard and the well sides, allowing the angle of incidence of the board to vary quite a bit, and not in a good way as would be something like a well-designed tacking daggerboard.

What i measured is that the board would actually be at a lower angle of attack to the water's flow compared to that of the keel line. Just opposite of what is required for efficient windward performance. Or even downwind performance.

So the fix was to position the centerboard in the fully down position, grind the well/hull to allow for a proper angle of incidence, then fill the gaps between the board and well-bottom with thickened epoxy. 

Test the incidence again....

Then position the board in an 'up' position, but without the pivot pin installed so that the board could be pushed down far enough past the bottom of the hull/well so that the thickest foil sections of the board would be right at the bottom-hull/well interface. 

Then fill the resulting gaps with more epoxy....

Trim the cured epoxy so that the board can be raised and lowered without binding or drag....

And drink a cold, dark Guinness Stout on the deck.  Ah!

Next job will be to vacuum-bag some style 1700 'glass/epoxy reinforcement to the keel line of each hull. Then fair and gelcoat just the 'glass repairs.... for now.... gotta get that cat into the water to race!

So... thinking about an appropriate name for the Mystere 6.0....

GRIMALKIN!

Perhaps 'Greymalkin'.... or 'Graymalkin'.... Shakespeare, Macbeth ya know.

Perfect for an old, gray catamaran.

Yeah, I know all about the infamous 1979 Fastnet race. But that boat survived to race a year later!  Anyway....

Whadya think guys?  Cat got your tongues? 🤣 

Boy, this forum is sloooow in the heat of the summer. Hope sailors are having fun sailing!

I've been working diligently on the ol' Mystere. Yeah, and the F18 C2 a bit.

This is the Mystere 6.0 thread, so here's some progress notes:

I glassed over the centerboard wells on the bottom of the hulls with two layers of 4 oz 4-harness 'glass so that I could vacuum bag the full keel length. Yes, when all the glassing and fairing is complete, I'll cut out the glass over the wells. No problemo.

So far the vac-bagging is going swimmingly on the port hull's keel. Since it's been in the high 90's and 100's (deg F) these past weeks, I've been using West Systems Extra Slow hardener. I also have been only laying up and 'bagging two lengths (50") of 1700 biaxial with widths of 7" at a time, for a vac-bag length just over 100". I've found that I have plenty of time, even to spare, with that method, before the vac pump is turned on and the few tiny air leaks are fixed.

Today I have faired a couple heavy dent faux-pas' on the sides of the starboard hull. Last night I had glassed in those dents (after grinding the damaged f'glass to the pvc core) with just a hand-layup of fast epoxy (West system) and roughly eight layers of 4-oz 4-harness 'glass, and squeegeed the excess resin out of the layups with 6mil plastic sheeting over the layup. This morning I DA-sanded those repaired areas flush, but of course there were very small indents left, so a bit of fairing compound fixed that. I'll add a couple more layers of the 4-oz glass to those repairs later.

I don't know why, but I missed spotting vertical gelcoat cracks on the transoms of both hulls. Fudge. That means more gelcoat grinding and more laminating. Whatever. This boat is requiring a lot of love to get back to sailing.

Above: results of vac-bagging 1700 biaxial at transom to 100" forward. Super-tight lamination! Perfection... so far.

You can see the gelcoat crack on the transom. 

Bottom of centerboard well glassed over for vac-bagging. Forward of the well you can see the newest vac-bagging in process.

Vac-bagging that I completed yesterday. I haven't taken pictures of the results yet, but it came out perfect.... better than I had expected. The bagging materials had a longitudinal wrinkle all along the keel centerline that I was concerned would create a wrinkle in the laminate. But no worries mates! The final laminate came out without wrinkles!  Phew! I've had other Vac-bagging projects where if there were wrinkles seen in the bagging material after the pump came on, then the final product had wrinkles as well. 

I think what happens is that, especially on a convex surface, as the whole stack height of the laminates and the bagging materials compress with applied suction (atmospheric pressure), the outer bagging materials (peel ply, breather, bag) now have to cover a shorter 'circumference' or smaller surface area, so they tend to bunch-up a bit and create wrinkles in the bag. Sometimes this bunching telegraphs to the laminate, which is not good for the laminates' ultimate tensile strength and may lead to fairing compound and gelcoat cracks later on. This scenario might also happen if too much resin is in the laminate to begin with, and as the excess resin is sucked out, the 'glass compacts and contracts more than if that excess resin was squeegeed out before bagging.

It's good practice to sqeegee-out most of the excess resin from the laminates before placing them on the surface to be 'glassed, especially if the surface has some contour and/or shape that makes it difficult to squeegee.

What? Yes, I saturate the 'glass with resin while it's on the laminating table. The table has 6mil plastic sheeting taped down, then pour a bit of resin on the sheeting, then lay on the fiberglass cloth. Pour on some more resin, spread about, then add another layer of 'glass if the laminating schedule calls for. Place another sheet of plastic over the wetted-out laminates and begin your squeegeeing process, pushing the resin to dry areas. If you find it very difficult to wet every fiber, carefully lift up the top sheet and apply a bit more resin.

Once every fiber is saturated, then squeegee as much of the resin out of the laminates as you can, pushing the excess resin off the edges of the laminates. A slow hand with pressure while 'pushing' the edge of the squeegee blade does it best. (Dune!)  If wetting-out separate laminates as I am doing in this project, one after the other, and while the resin is still workable, the excess resin can be used again. 

It's a good idea to wet the surface to be laminated with very light/tight coating of neat epoxy, just to fill in any imperfections and porous areas.

Then, carefully peel off the bottom (or top, your choice) plastic from the wet laminate, carefully place the wet side on your surface to reinforce.  Then carefully peel off the now top plastic, keeping all the 'glass threads from pulling off the surface with the plastic. Afterwards, go back and gently squeegee the new laminate down to the surface, reducing air bubbles under the laminates. The cool thing is that the vac-bagging will take care of any and all air-entrapment, but being sure that the wet laminate is solidly down on the surface will reduce the possibility of wrinkles in the final product.

Really, it's not too tricky to get excellent results. I love vac-bagging, er.... I mean I love the results.

Anyway, that's all I have for ya all today.

P.s.

It would be nice if there were some form of response to these posts. Whether positive or negative feedback... something is better than nothing!

I'll continue to post my progress just as long as I figure other sailors are getting something out of these posts . 😉 

Posted by: @cat-scratch

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It would be nice if there were some form of response to these posts. Whether positive or negative feedback... something is better than nothing!

I'll continue to post my progress just as long as I figure other sailors are getting something out of these posts . 😉 

I am following closely! Great stuff. Impressive, not many home repairs include vacuum infusion! 

Thanks Damon! 

Just a little correction to your statement so there's less confusion on the processes,  the laminating methods I've been using here are not as complicated as vacuum 'infusion'.... it's just basic wet-layup with vacuum bagging.

Infusion requires very low viscosity resin of around 200-300 Cps (Centipoise), whereas the West Systems Extra Slow resin/hardener is around 650 Cps , the Slow hardener is around 750 Cps, and the TotalBoat 5:1 slow hardener I've been also using is around 700 Cps, so infusion would be impossible with these resins.

Also, infusion requires a good amount more of resin in reserve, fed from a central pot, or array of pots, into the the pre-placed dry laminate and bagging stack by multiple hoses and resin dispersion mechanisms (spiral wrap, flow media, etc.) that complicate things quite a bit. 

Wet layup vacuum bagging is far simpler and less costly for the home DIY dude for small projects like this. 

If I was building, say, an F30 cat from the ground up, then YES! I'd explore VARTM (vacuum assisted resin transfer molding) better know by most as 'vacuum infusion.' It's a very clean method of laying up a hull... if your flow calculations are correct. Lots of possibilities for making little errors that could ruin a whole hull, or make repairing those errors much more time consuming.

Thanks Damon!

https://jotaintl.com/about-us/academy/vacuum-assisted-resin-transfer-molding/

@cat-scratch Thanks for the clarification! That is what I get for trying to use terms I don't fully understand. I haven't tried any fiberglass work myself but I'm always up to learn something new.

Posted by: @damon-linkous

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 I haven't tried any fiberglass work myself but I'm always up to learn something new.

Cool!

So, you CAN teach old cats new tricks. (No dogs allowed!)

I'm referring to myself.... I just learned a new trick! 

So I was prepping the port hull (yeah yeah yeah.... I got the hulls mixed up in my last post) for the first installment of wet-layup vac-bagging beginning at the stern, progressing foreward, just like I did on the starboard hull. 

I rinsed and scrubbed the areas to be laminated with water and a SS scrubby (SS wool). Dried everything off and allowed the hot sun to do the rest. Then rolled the hull into the cooler shop and pre-placed the vac-bag (6mil plastic sheeting from Lowes home improvement -- works well enough!) and taped one of the long sides (3M vinyl electrical tape works just as well as vac bag mastic tape, and far less expensive). The hull was sitting there in the warm shop. 

What?!? How did water get under the plastic bag?! Wait.... there's a few places where water is appearing! 

So, dried off those areas and replaced the bag. 

Again! What gives?!

Ah..... little tiny holes in the original laminate. Fudge.

Out came the DA sander with 40 grit. Time to go medieval on these areas. Nothing like taking out your frustrations on a poor cat. (That doesn't sound right).

I remembered that there were a lot of gelcoat cracks on this stern area, so no wonder. It likely got slammed while offloading the cat from the trailer  a few times. Maybe.

Above, you can see a good sized area ground down on the right of the upside down hull, and a smaller grind on the left side. I kept on grinding until there was no loose laminate on the pvc core.

This one above is on the right side of the centerboard well's leading edge. Remember I had 'glassed over the well opening for the upcoming vac-bagging process. This boo-boo kept on growing longer as i found more and more loose laminate. It's about 1.5" wide by 5" long.

No problemo.  Just came back inside to cool down and stop sweating all over the place.

yeah.... at first i thought those wet areas were merely sweat drippings from my forehead. 

Nope. 

So what's the moral of this tail, er, tale?

When in doubt about little tiny core leaks, place some plastic sheeting over the area in question. The condensation from the water in the core will create a wet-looking area under the sheeting! Super easy to find those pesky holes. Especially if you believe that your cat has experienced a lightning strike. I've heard that a lightning strike doesn't necessarily create a big blown-out hole in a hull. Many times it creates a bunch of almost-microscopic holes that are very hard to detect just by sight.

It might be a good idea to first wash the hull well, dry it off, then do the plastic trick. 

So you're asking.... whatchya goin' to do now?

I'll just wet-layup a bunch (10+) layers of 4-oz 4-harness 'glass with the west systems fast hardener, starting with the largest pieces and ending with the smaller pieces. I don't mind wetting-out these small repairs right on the boat. But I will squeegee most of the resin out so that I can get a fiber-rich layup, rather than a resin-rich layup which would be more brittle and have less 'strength.'

Then after cured, just sand it down to flush with the existing surrounding laminates. Sometimes I haven't allowed for enough 'glass to prevent a shallow divot after sanding, so I can fill that with a little fairing compound, or laminate in some more 'glass layers.... whatever I feel is most appropriate for the repair area. If it's in a high-stress area like near a centerboard or daggerboard well, or a transom, or near a chainplate bulkhead, then I'll make sure that the repair is ALL fiberglass, no fairing compound.

Hope this helps someone.

Long live old cats!

To continue with those areas that I ground down to the core, here are a few pix of the repair laminations.

In this above pix, the bottom-most hull has the most recent repair near the centerboard well and keel line. Roughly 20 layers of 4oz 4-harness 'glass and 6oz unidirectional glass in alternating layers, and epoxy (fast hardener) were laminated, then 6mil plastic sheet laid on and the resin squeegeed back and forth to help saturate all the fibers. The plastic remains on until cured. This also will help keep the humidity away from the curing resin and help prevent amine blush from forming since it's quite humid here. High humidity promotes the precipitation of the amine blush.

The starboard hull in the upper part of the pix shows another repair done with the same method, though I haven't gotten to sanding it down to level.

Above are the repairs at the transom. Yeah, not so pretty since I mistakenly used some old plastic sheeting that had cured epoxy still clinging to them. That won't be any problem, though. Again, roughly 18-20 layers of the same style of 'glass.

Above is yet another repair done on the port hull, roughly about amidships. This also was done with the indicated method of laminating, then it was sanded reasonably fair for the time being. It might require just a hint of fairing compound to make it perfect, or not, as I haven't taken a straight edge or fairing board to it as yet.

Yeah, she's receiving lots and lots of love.

The name of the game is to get her in the water as fast as I can, while still ensuring that she's up to the stress. So, she's not going to be receiving much gelcoat this season.... maybe just enough gelcoat on the keel to protect the new shoes she'll be sporting.

Yes, I believe GRIMALKIN will be the perfect name for her. 
Old, weathered, gray, faithful cat.

These are big repairs and a lot of them. I have done some major hull repairs on my now deceased N5.7 but that was a solid laminate construction with no foam core. What are you using for a vacuum pump?  You clearly have some expertise in composite repair or lamination. 

I'm using a wet-vane HVAC pump of rated at 7 CFM's. Purchased this way back in early 2000's for vac-bagging. Back then, it was JB Industries biggest baddest pump. Got it on sale. It's been a rock-solid machine for around 24 yrs now. Of course, periodic oil changes and complete interior clean-outs once in a great while help keep the carbon vanes from wearing and pumping to specs.

JB still makes the very same pump.

https://www.jbind.com/product/platinum-7/

I'd believe that any wet-vane pump, such as a robinair, or even something from harbor freight would work fine. The only time when you need a lot of pump volume (CFM) is when doing large repairs on big stuff. My pump is quite overkill on what I'm doing right now.

A dry vac-pump (piston) would be nice, but they're far more expensive compared to wet-vane pumps, unless they're made of chinesium, and those would not be very long lasting.

I've found that the Robinair Premium vac-pump oil is possibly the least expensive wet-vane pump oil and is just fine. One gallon has lasted a couple years worth of oil changes. I change the oil about once a year or when the oil becomes a little cloudy-looking or slightly colored. Of course, if somehow there is moisture getting into the pump through the bagging process, then oil changes should occur more regularly. If the hull core is wet with water, then I can use the pump to help dry the core out if it's not feasible to outright remove the core. That usually happens on bigger sailboats (yachts). Then you have to be very careful about keeping any water/moisture out of the pump.

Funny, my first small vac-bagging project back in the 1990's I tried using the intake side of an air compressor for a vacuum source. It worked.... until the pump failed due to heat build-up. Expensive lesson. 

Speaking of heat build-up.... my wet-vane vac pump generates quite a bit of heat.... I measure it every time I bag... the pump gets up to around 160 deg F. and the motor gets up to around 150 deg F. in a warm shop environment (~85 deg F). I put two small fans blowing air on the pump side and they keep the pump temps down to around 125 F and 135 on the motor side.

For small projects (beach cats, dinghies, etc) I made a simple water/moisture/residue catch 'system' that is made of a 3" pvc pipe of 3ft in length, capped on both ends, (pipe length positioned vertically) with the very top exit hose barb going to the pump, and the intake hose barb coming in to the side, mid-height, and at a tangential angle to the interior pipe wall so that there is a counter-clockwise rotation of air that helps push down the moisture and possible micro-fragments to the bottom of the catch. Seems to work well. The other day I broke it open to clean it out.... there was some form of wet/oily grunge with some black particles on the bottom of the catch, but the vac-pump oil was quite clean, still.

I developed my first ideas of vac-bagging after reading Eva Hollmann's website.... she's past away a few years ago, but back in the '70's through the 2000's, she was a force of yacht and sailboard sailing, naval architecture/yacht-design, and yacht construction. She had her own shipyard, designing and building some very impressive racing yachts that won many races, back in the 80's. Every once and a while I'll review her site, as well as others just for fun.

https://boardlady.com/index.htm

Another note about wet-vane vac-pumps.... their exhaust is an oily mist that will be quite nasty indoors. I have my pump on a shelf in the shop, and have connected a vinyl 3/4" ID x  ~3' long hose to the exhaust located on the handle, and pipe that outdoors through a small hole in the steel shop's interior wall, insulation, and siding.

For vacuum tubing, I'm just using cheap 1/4" vinyl tubing from Lowes/Home depot.

The tubing is connected to a hose barb that is epoxied to a epoxied wood plate (vac-port) that looks like a big washer of approximately 2" diameter. After placing the bleeder media and before placing the bagging material, I place a 1.5" diameter steel washer (3/4" bolt washer) some place equidistant from the far ends of the bag. The washer is meant as a flat backing plate for the vac-port. The bag is now completely taped down, I then make a small hole in the bag in the center of the backing washer, then add vac-bag mastic tape to the bottom of the vac-port, and stick the vac-port onto the bag, centered on the hole I just made. While holding the vac-port in place, I turn on the pump. It take maybe 5 seconds for the bag to be completely evacuated of air. For larger bags, I will have multiple vac-ports with T's in the vac-lines.

The fun isn't over after turning on the pump.... now to find all the air leaks! If you've done a good initial job of sealing the bag, the air leaks will be almost silent, but there will likely be a few. I put one end of a vinyl 1/4" ID tube in my ear, and the other end is used as a stethoscope searching for the tell-tale high-pitched sounds of a leak. It works very well. The leaks are usually at bagging creases and at the vac-ports.

Have fun!

I just (doh!) figured out why that vac catch-can had wet/oily liquid in the bottom of it.. maybe about three ounces worth when I opened it up to inspect and clean it. 

When I had discovered that one of the hulls of the F18 C2 had a wet core just forward of the dagger well, I had drilled quite a few 1/16" holes in the exterior laminate, into the core, and vacuum-bagged the hole area to try and evaporate all the moisture trapped in the core. The bleeder material didn't look too wet, but that could be because the water evaporated from the bleeder as well. 

It's most likely that the entrapped water became vapor (the pressure within the vacuumed area became lower than the vapor-pressure of water) and went into the catch-can along with some sort of oily liquid that likely had a much lower vapor pressure. The water vapor likely went right through the pump, while the oily substance stayed within the catch-can.

I ended up removing the outer laminates as well as the wet core and replaced all that I excoriated... with vac-bagging of course.

I do believe that if I had kept the vacuum on that wet core area long enough, maybe 48 hours or so, then it's possible that all the moisture would have been evacuated, and I could have merely injected some neat epoxy into the holes.  But now I am absolutely positive that the repair is just as strong, likely stronger, than the original construction.

https://thebeachcats.com/forums/technical-help/2010-goodall-c2-f18-refit/#post-346096

I believe I'm done with grinding fiberglass.... for a while at least. 

So itchy in the heat!

The vac-bagging of the biaxial 17-oz glass/epoxy on the keels worked out great. 

Above is the starboard hull. In the rain today. The bow got a slight face-lift.

The previous owner butchered both hulls' stems with a grinder, likely trying to find solid 'glass through all the bondo, so their original profiles were impossible to discern.

No problemo.

So right after applying a wet-layup of some biaxial 'glass/epoxy over the stems, I clamped onto one side of the bow a 2'x1'x1/8" piece of Kydex that I had left over from my holster-making days. I waxed the smooth side of the Kydex so the epoxy wouldn't adhere to it too much. It created the perfect form for transfering the hull's elliptical bow sections into a proper stem profile. I believe the original stem profile for the Mystere was more of the classic, straight, slightly angled forward at the deck - shape. So now the stem is extended maybe about one inch further forward, and makes a nicer, smoother entry ...  kinda axe-shaped.

The next objective is to begin the fairing process. So much fun.

Above shows the initial applied notched fairing compound (West Systems Slow with Microlight filler). This was applied with a notched 6" long plastic bondo spreader that I had modified on the table saw. Saw kerf is about 1/10" wide, with each saw cut roughly 1/16" deep and 1/4" apart. Super-easy and quick to make. After a few of filler application, the plastic edge gets worn down a bit, so back to the table saw to deepen those notches.

The nice part of the notched filler is that it's only roughly 1/2 of the surface area that is required to fair and sand, so fairing with a long board is pretty quick and requires less elbow grease.... AND.... requires less total fairing compound to boot!

After I'm happy with the fairness, I'll go over the notched surface with more filler and completely smooth over all the notches, then sand with the longboard once again, though it will require merely a touch-up at this point. Though, it may require a bit more filler and sanding. Somehow the fairing process always does. When I'm satisfied and after a couple days of curing, it should be ready for gelcoat!

"What?!"

Ah, yes.. that old boat-builders' wives' tale....

"Don't you know that gelcoat doesn't adhere to epoxy?!"

Yes, it will. But if you mix the epoxy with just a bit more hardener than is optimum, then it won't. Nor will it adhere if the epoxy hasn't had a chance to cure completely. A good hot 100 deg F. day or two in the sun will help.

I was hoping to be a little further along with the Mystere's progress since the next race is this coming Saturday.... yeah, race a boat that I've never sailed before and has just left the repair shop. What could go wrong?! 

Eh... it's all fun and games.

Yeah, it's Monday, and it's raining. So It's very likely that I'll be racing the H16 again this next regatta.

I'm liking that stem profile! Like something out of a thriller movie with a cat wielding a razor-sharp battle-axe. Right.