the dirty work looks almost complete ......looking good so far
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| 21 Scarab SOB Overhaul - Pic Heavy http://hpbc.ca/viewtopic.php?f=20&t=2656 |
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| Author: | Dougw [ April 6th, 2015, 7:24 am ] |
| Post subject: | Re: 21 Scarab SOB Overhaul - Pic Heavy |
the dirty work looks almost complete ......looking good so far
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| Author: | OMCFORME [ April 13th, 2015, 7:42 pm ] |
| Post subject: | Re: 21 Scarab SOB Overhaul - Grinding Fun |
Thanks Doug, it has been keeping me out of trouble  So I spent a lot of February and March grinding.....Didn't take a lot of pics of that, familiar story - 36 (or 24) grit and have at it... This boat is a little different than others. Those grooves are the strakes. The stingers sit in then, as opposed to having foam or putty-filled strakes. I suspect it made dropping the stringer grid in place much quicker. Oh yeah, you know the age-old debate amongst boatbuilders about what to bed stringers in (i.e. putty/Corebond vs. chopped-strand mat, vs. epoxy vs. Plexus ya da ya da) ? Well Wellcraft didn't buy into that - let's not bed them at all ! That's right - they were not attached to the hull other than the tabbing. Came out real easy   I'm taking it back to solid woven roving. The narrow belt sander is very handy for making nice radii in inside corners.  Also cut out the other side of the cockpit floor pan. 
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| Author: | OMCFORME [ April 13th, 2015, 8:06 pm ] |
| Post subject: | Re: 21 Scarab SOB Overhaul - Stringer Fitting & Install |
So finally getting to some fun stuff. Bought some marine-grade 3/4" fir plywood and had it ripped to width at the yard on their big panel saw. I want full-length stringers to the main bulkhead at the forward end of the cockpit. That amounts to about 11 feet, so obviously 8' plywood will not cut it. You can special-order longer lengths but not worth the money, I'll just scarf the plywood to length. I've done lots of this before. I'm doing an 8:1 ratio scarf, more than adequate for an epoxy joint. There's lots of ways to cut these but I just use a sharp hand plane. If you have a power plane with carbide knives that's actually the best way. I have overlapped the 2 pieces end-to-end and screwed them to a back-up board so there's a stiff "stack" to work away at. I "wasted" a lot of the material with a chop saw first.  80% done the scarf. You end up using the plies like "contour lines" to ensure you cut a nice even slope.  And here it is being installed. The stringer is bedded in WEST 610 epoxy (great stuff, comes in a caulking tube). I used regular WEST (thickened with cabosil) to glue the scarf.  The "shelf" above the strakes is somewhat wider than the 3/4" stringer. This results in sharp inside and outside corners that you'd have to wrap glass over. As a result, the factory layup had a really bad air pocket all along the inside corner of the stringer tabbing (not unexpected with heavy roving). It helped distribute water along the stringer - a no cost option  (as you can tell the build quality on this boat was VERY production - if you ever thought Scarabs were superior give your head a shake). Anyway, I'm doing fillets with epoxy to solve this problem. I trimmed a plastic squeegee to nice radii and trowelled it in. You can sort of see the scarf - my black pen line I used to align the "knife edge" of the forward piece. The top of the stringer was rounded over to a 1/4" radius prior to installing (also not done by the factory). Next I'll start tabbing them in with 1800 45/45 double-bias ("biaxial") in epoxy. 
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| Author: | talonkid [ April 13th, 2015, 10:10 pm ] |
| Post subject: | Re: 21 Scarab SOB Overhaul - Pic Heavy |
Wow that's lots of work to do but the quality shows. Looking good. |
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| Author: | DoktorC [ April 13th, 2015, 10:34 pm ] |
| Post subject: | Re: 21 Scarab SOB Overhaul - Pic Heavy |
Awesome!!! You'll need a lexan floor so you can show your work lol. |
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| Author: | OMCFORME [ April 14th, 2015, 5:42 pm ] |
| Post subject: | Re: 21 Scarab SOB Overhaul - Pic Heavy |
Thanks guys, there's still tonnes of work to go but it starts to feel good when the new stuff goes back together how you want it. More pics to follow as the glass work progresses. Matt |
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| Author: | OMCFORME [ June 24th, 2015, 10:46 pm ] |
| Post subject: | Re: 21 Scarab SOB Overhaul - Pic Heavy |
Well I haven't had much time to work on it due to house projects, but here's some updates. I decided to do the repairs on the splashwell before putting the second stringer in. I have a lot better access to the underside of the well with it out. The glass work on the splashwell wasn't very good. It was cracked on both sides near the bottom, and there was a crack in the exterior portion of the well where it meets the motorboard. I ground away the bad glass and laminated in 4 layers of 1800 biaxial.  I then built a cross-member out of 2 layers of 3/4" marine fir plywood epoxied together. This then was bonded into the under side of the splashwell, running from one knee to the other. This adds a lot of strength to the transom. There's a notch in the cross-member to later accept another knee down the center of the transom.   The crossmember will then get glassed over as well. The splashwell had 4 holes that needed patching. The forward side of the well is plywood-cored. One of these holes I hole-sawed out as a gelcoat sample to send to Fiberlay to get some computer-matched gelcoat. The other was an old rigging hole for the old Hynautic steering. Two old rigging holes on the starboard side were glassed up first from the inside, then I'll do the same on the outside.   I hole-sawed new plywood plugs, and epoxied them in place, using little blocks of wood hot-glued in place to hold them. Worked great. They will now be glassed up from both inside and out.   Obviously this thing won't be in the water this season. No problem, I'm more concerned with getting it rebuilt right. |
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