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HighDesert

Utah OB20

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I use a belt sander on these issues. In practiced hands, this makes quick work of a reshaping. Be careful, as it'll remove a lot more stock than you want very quickly, so kiss it and check, repeatedly. If still too fat visually, round over the edges with a generous radius,so it rolls into the eventual half oval footprint area. This treatment will add a nice shadow line along the half oval, making you look like a pro. The key is to get is straight, so the half oval doesn't have to wander around finding the center on the stem. A trick I use is a length of tape, eyeballed down the centerline and working to this on the shaping and corner radius efforts.

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HighDesert,

I had the same problem when I came to the shaping of the stem. the simplest way for me (and being a metal worker by trade) was to install a full length keel band, 1" wide. I mirror polished the first 6 or so foot then left the rest the natural finish on the s/s flat bar. I probably should have asked the more experienced guys in the forum first! I hope this wont cause too many problems with the performance of the hull......I don't think it will, but it's too late now to worry about it.

Keen

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12 hours ago, HighDesert said:

... A question regarding the stem profile.  I may have made it too blunt.  Alan says it should be okay with a half round metal strip on it.  Any other comments on this issue would be appreciated.  I don't mind doing the extra work to build it back up, if that's the correct thing to do.

 

Thanks,

Carter

 

I wouldn't worry about it from a hydrodynamic standpoint, it will probably be fine.  It's really up to the builder;  Blunt will be less susceptible to damage.  The nice part about building this way is that you can easily glue some lumber back on and make it any shape you want.  I would probably add material and reshape to a finer edge but that's just me.

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Ken,Just for information, kregg makes pocket screws in stainless steel also. I used some a few weeks ago in a transom I epoxied up. They can be left in on some applications.

 

Scott

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Outside of having the extra area outside of the metal, its important that the end grain of the hull plywood be sealed for long term durability. Personally I use some hardwood to cap the sanded edge and then shape that before tabbing over the added finished edge. Its really important that you be mindful of using quality bedding compound for the metal and screws. While we think that the screwed bedded in 5200 type bedding will never leak, this is not always the case, especially where repeated bumping for loading on rollers on a trailer takes place. This will allow some creeping and wicking over time for dampness to follow the fasteners into the wood grain of the hull. But you can see some discoloring over time around the areas of the heads if you check those areas on occasions down the road.

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I knew I could count on you guys for great comments and suggestions. Much that I hadn't considered. Thank you. I'll continue punishing that longboard as I contemplate exactly how I want to proceed with the stem. 

 

There'll for sure be paint and painting questions later. 

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Keen, thanks for the tips and photos.  I've followed your progress; your boat is beautiful and your incredible metal work makes it very special.

 

I thought I might not need to post with questions again, until selecting paint products and techniques, but not so lucky.  

  • I've read that some people feel strongly about pre-coating the hull with resin before laying the glass and some don't think it's necessary.  Regarding the pre-coat "dry" method, is it necessary to cure, sand and clean the pre-coat resin before laying the fabric, or is it feasible to think one could catch it in the window between tacky and fully cured?
  • I also read about Peel Ply somewhere on the forum.  Some people (a few...maybe it's a very new product) say it's revolutionary and will never do another project without it.  Others say it's expensive and not worth the bother.  I'm thinking the whole boat needs to be thoroughly sanded before painting anyway...and possibly between subsequent coats of epoxy;.  Does it really save that much time?  For one reason, or another, I've lived my life doing most everything the difficult, slow and frequently not-so-smart way, but I'm open to a sanding short-cut, if there really is one. 

Carter

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Carter,

I like to precoat and let it partially cure before applying the fabric.  Depending on the epoxy you are using, you can let the seal coat get dry to the touch and still get a chemical bond without sanding.  System Three, for instance, says you can wait up to 72 hours before you need to sand.  As long as you can lay the glass down without it sticking in that time frame you are all set.

I have not had great luck with peel ply on large surfaces.  I have used it for smaller vacuum bagging projects but have had nothing but grief on large areas.  That said, lots of people swear by it. 

Enjoy.

Ken

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The bottom line for waterproofing things is the film thickness, which just about every epoxy formulator suggest should be 10 mils. Normally applied (roller, brush, etc.) you need three coats, to get this thickness. Now, if you apply fabric directly to the surface, which hasn't been pre-sealed with epoxy, you can get 10 mils, but there's stuff in there that isn't actually epoxy (fillers, fabric, etc), which artificially bulks up the film thickness.

 

In short, the surface that gets a sheathing (fabric) should be sealed with at least a single coat of straight goo, before a fabric goes down. This insures the substrate isn't going to suck any resin out of subsequent coating or sheathings and provides a uniform base for the fabric to grip. I've done both the tacky and dry to the touch, but still chemically active methods and both work. The tacky method can be messy, so can the wet method (pre-saturating the fabric) and I don't recommend the wet method for novices. The tacky method works good on vertical and overhead surfaces, but can be more difficult to manipulate the fabric (tug and stretch it), so I use the dry method, which has a previous sealing coat of epoxy, that's dried and either still chemically active, but dry to the touch or a previous coating that's been washed and sanded lightly for good tooth.
 

With experience,  you'll find if you lay 'glass fabric on raw wood or plywood, you'll also find areas that seem less "wetted out" then others. These ares will look slightly less transparent, maybe have a slight whitish tint, etc. These are the areas where the raw wood, sucked a little more resin than surrounding areas, slightly starving the bond line between the fabric and the wood. These "dry spots" are obvious when simply coating raw wood and we just go back and apply a little more in these spots. Under fabric,  these are much harder to anticipate.

 

Like most things, materials (peelply) need to be utilized in the areas they work and avoided when they aren't as good. I use much less peelply then I once did. I have different application techniques now, which makes this possible. All builders develop these "adjustments" to their methods as most learn the same as I, the hard way and have no choice but to adjust,  or simply learn to drink and curse more. Most can get buy without the bother of peelply and if this is a "one off" you really don't need to learn the in's and out's of this application technique. This said you can get better results if you're a quick learner, but you'll have to learn, which means you'll have to screw up and do things over and for some, the budget isn't worth this level of "expertise" or understanding.

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You guys are awesome, thank you. 

 

I know just how I am going to proceed.  Drink, curse, screw-up, drink, curse, learn, adjust, drink, smile...next problem.  Having this forum is like having friends help you build your boat.  Maybe even better, my friends don't have a clue how to build a boat.

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Well cool. When "we finish up your boat", can we  get free beers and the occasional ride too . . . ;)

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Further to PAR's suggestions regarding peel ply, I agree with his recommendations re whether to bother with it.

I've used it extensively in the manufacture of epoxy windsurfers 

These boards typically receive a sheathing of 2 layers of 6oz fabric.

Be aware with peel ply you can end up with tiny 'pin holes' in the final laminate depending on your methodology.

Ie. little voids between the fabric weave.

They are a pain to fill and are often invisible until you start laying down paint.

I've even had an instance where a pin hole let water into an underlying sandwich core.

In summary, be cautious using peel ply if you are going for a thin sheathing layer.

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That settles it; no Peel Ply for this guy.

 

Well cool. When "we finish up your boat", can we  get free beers and the occasional ride too . . . ;)        PAR, this may be a good deal for you.  I've been brewing beer for a lot longer than I've been building boats.  I'm easy to find.  "Just head west, until you get to the Rocky Mountains, then turn right...Pilgrim."  Not exactly accurate, but I've been wanting to say that for years.

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Maybe I've rated a emergency care package, of course simply to critique the latest batch . . . B)

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You rate it for sure, but I think sending it to you might be considered bootlegging in Utah.  Strict laws here, otherwise I'd be making gin.  You just might need to make the trip...for the beer and the boat ride.  A better route than the one I mentioned before would be to head west until your smell weed.  That's Colorado; keep going.  I'll talk you in (down?) from there.

 

More seriously, on your blogspot, you discuss leveling and smoothing as the two parts of fairing.  You also talk about using a spray can/sanding technique to help with leveling.  I'm guessing that 95% of the leveling should occur before any epoxy/fiberglassing and the spray can/sanding trick comes afterward.  Correct, or do you do the spray can trick during the earlier leveling on raw wood?

 

I probably should be too embarrassed to let anyone see the photo below, but I guess I have no pride at all any more.  After installing all the hull panels, I identified all of what I considered to be the "hard" spots and went after them with my random orbital sander to "save time".  Holy Hell, what a job I created for myself.  My wife asked if we were going to name this boat Mr. Potato.  The second picture doesn't really tell the story, but after days with the longboard, it's much better now.

 

I love this hobby.

 

 

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If you love this hobby after time behind a longboard, you are hooked!  Are there mental health services in your part of the world?:)

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Yeah, that's about as classic an example of an "unfair" surface as you could ask for. This is common with wood and epoxy work. The epoxy is much harder than the surrounding wood, so if you hit it with a sander to remove a drip or pile of goo on a fastener head, you grind down the epoxy all right, the the softer surrounding wood take a beating too.

 

A fair surface is what you can see. These appear as waves, undulations and other defects in the actual surface, such as the big divots you'll need to fill above. Some of those look deep enough you'll hit them twice at least with filler and maybe want to add some fabric too.

 

Do the fairing part first, as smoothing is just leveling the coatings, be these paint or goo. This process (smoothing) is called a few different things, but it's a surface coating treatment, like knocking down stipple after spraying paint or roller work or flattening brush strokes after hand painting. This process doesn't need fillers (usually) though some high build primer may be required to fill in deeper imperfections.

 

Fairing is mostly "board 'o pain" stuff and you progressively identify and knock down the high spots, while also fill the lows. The first pass with the long board will ID the highs and lows, for more attention. A light misting with a contrasting primer can help a lot, as the high spots will get the primer removed, while the low spots will still have primer in them. I usually knock the highs down and lightly mist again to see how close these are, as the lows are still there and need to be filled. Some will fill with primer, while others (see above) will need filler. For most novices, I'd recommend a premix like QuikFair, from System Three. Fill the lows and knock them flat(ish) with a long board, leaving the other areas unattended until you've got the just filled area close. Mist with primer again and more board 'o pain time will ID, how much more needs to be sanded or maybe you need more filler (don't be surprised if you do). This is repeated, until you can go from one end of the boat to the other, after a light primer dusting and no highs or lows show up. This is where the sheathing can go on, though I like to seal the surface with straight goo, to lock down print through (tape) and the fairing compounds. Some smoothing can been done, before the sheathing, but generally it's not necessary, as you'll be doing this on the finish coats, assuming you got the sealing coat pretty smooth and didn't put it on with a wire brush.

 

Once the sheathing is on, you'll go through the contrasting primer routine again, to find more areas and irregularities. You can get as anal as you like about this, but most just toss their hands up and surrender at some point.

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PAR, thank you. I understand and I'm on it. 

 

Ken, mental health services?  Up until a few weeks ago, all I needed was an hour or so in the gym, or maybe a little Pickleball with some other old people. Now I sand. 

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Carter,

There is nothing like a cloud of toxic dust and aching arms to make you feel sane ! Keep up the mental health work! It is only a non - boatbuilder that would call you crazy and what do they know?

K

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