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Walt S.

Spindrift 12 build log

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Walt,

I'm responding to a discussion that you all had way back on page one.  Since it is a health issue, I want to chime in on the subject.  I never wash my hands with solvents of any kind.  I was told that they all drive epoxy into your bloodstream-- not good.  As long as the epoxy is green, vinegar will cut it.  I have a spray bottle full of vinegar in my shop that I use for just this purpose.  If I find a spot on me where the epoxy has gotten past my line of defenses, I spray it with vinegar, and wash it with soap and water.  That usually does the trick.  If it doesn't, wait until it is cured.  Don't be tempted to use solvents.  Another way epoxy can get you is when sanding.  That epoxy dust is also not good for you.  Wear a dust mask.  Finally, I have found that the "fumes" do not agree with me.  I know that epoxy is nearly odorless (at least to me).  But every time I don't use an organic vapor mask when handling large amounts of it, I get a headache.  If I'm mixing a small batch for gluing, it's not a big deal.  But if I'm filleting or laminating, on goes the mask.  I wanted to share these thoughts with you earlier, but it was difficult to get to my laptop.  Good luck with your boat.  She's looking good!

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Thrillsbe, 

 

I'm only using vinegar as an emulsifier when it gets on me.  Otherwise, I'm squeezing out as much epoxy as possible from paintbrushes and putting them in the freezer.  The epoxy can be broken off everything else I use, like mixing sticks and spreaders.  

 

Guys on the forum helped me realize acetone cost quite a bit itself, is hazardous, and not worth my time. 

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My dad and mom came up to watch the kids while my wife and I went to Mendocino county for a couple of days.  I badly wished my boat was finished for the trip because there are a several rivers that run into nice inlets in Mendocino county.  Before we left, we bent the gunwales 70%, left them clamped overnight, and then glued them on the following day:

 

post-5751-0-32033500-1475639312_thumb.jpg

post-5751-0-88691700-1475639315_thumb.jpg

 

When I got back, we leveled the sawhorses and then use shims, the aluminum angle irons, and a level to take the twist out of the boat.  

post-5751-0-45998600-1475639304_thumb.jpg

post-5751-0-76951800-1475639308_thumb.jpg

 

The transom was off when I checked for twist so I will have to re-check, but I like this method of untwisting a lot because it's easier to see if the bubble is centered on the level than if there is a disparity between winding sticks.  Winding sticks can show greater or lesser disparity in twist depending on lighting conditions, how true the sticks are, and the contrast between the colors edges of the sticks. Also, the aluminum was easy to find at home depot; quality winding-stick lumber is harder to find and they seemed like a pain to make.

 

post-5751-0-32949900-1475639282_thumb.jpg

post-5751-0-79942300-1475639285_thumb.jpg

post-5751-0-51401600-1475639289_thumb.jpg

 

Featured in the background is an epoxy-warming locker I made out of XPS foam sheeting and duct tape.

post-5751-0-08437400-1475639293_thumb.jpg

post-5751-0-81109700-1475639296_thumb.jpg

The shims are composite shims purchased from Home Depot

post-5751-0-72401600-1475639300_thumb.jpg

 

There was plenty of glue squeeze-out from the gunwales.  I removed it with a router and an edge-trimming bit and a block plane.  In anticipation of a lot of sanding, I bought some extension hose for the shop-vac I'm borrowing to connect to my DeWalt 5" random orbital sander.  

 

I pulled the #10 - 2" screws out of the gunwales attached to the breasthook and transom by holding the soldering iron on them for A LONG TIME and using a hand screw driver.  I've found that an impact driver just pops the heads right off of epoxied screws.  

 

I plan on tacking everything together this week after checking again for twist and getting the transom back in the right spot.  I was debating putting on the side stringers now but I've decided to wait until I've pulled out the temporary frame and glassed in the seams. 

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This brings me to things downstream: towing, abrasion resistance, and paint.  

 

Graham makes an iron-clad case for towing with a painter threaded through a reinforced hole in the bow above the forward compartment tied-off with a stopper knot.  This is also easier to make, cheaper, and lower maintenance than putting in a bow eye.  It also won't affect my flotation, which I will doubtless need.

 

Given that my boys will be using the boat, I might use it as a dive boat, and there are definitely rocky shores I'd like to bring it up on, several argue for using Xynole on the bottom.  PAR really likes the stuff.  There's an even chance the boys or I will run the boat into something, which suggests I use 10 oz glass on the bottom.  I should probably use some on the inside floor also.  I'm sympathetic to Dave's argument that a light boat is really nice to have though.  I'm strong; my wife is strong too, but the boys won't be for awhile.  The Xynole would add about 30% more weight to the bottom than 10 oz glass and it sounds easier to screw up than fiberglass. 

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Reading more on this topic, I think I just want to put on some HDPE sacrificial strips and Xynole only where I'll likely to get abrasions from beaching it. Does this mean Xynole first then HDPE strips?

 

10 oz glass up to the waterline is probably not a bad idea if I take it somewhere rocky, and perhaps 4 oz on the inside bottom.

 

Should I glass before putting on the keel?  

 

What about epoxy-based undercoats for painting? 

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Hirlonde-- Read the second paragraph of this from System Three:  https://www.systemthree.com/blogs/epoxy-files/83509380-section-ii-safety-and-handling 

And this is from West System:  http://www.westsystem.com/ss/how-to-prevent-overexposure-to-epoxy/

 

Oddly, neither mention vinegar as a clean-up product.  I will have to check that one out.  I figure that if it is OK to use soap and water for clean-up, then vinegar and water is OK.  It is definitely less intrusive to my skin than alcohol solvent.

 

Oh wait.  Here's an "official comment" from System Three regarding vinegar:  https://support.systemthree.com/hc/en-us/community/posts/213553227-Cleaning-up-cured-epoxy

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Thrillsbe that first link should be pinned since it steers everyone away from wasting time and money on solvents and clean-up.   

 

I've been wearing gloves and a respirator.  Usually there's a pile of gloves on the floor after I do an epoxy job because they tend to break.  I should probably start doubling up on them and wearing long sleeves.  

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If a liquid can dissolve epoxy it is a solvent of epoxy. 

 

2 :  that dissolves or can dissolve   http://www.merriam-webster.com/dictionary/solvent

 

I am not saying all solvents are equally safe, just that your comment was inaccurate.  In a technical discussion like this accuracy and comprehensiveness  are extremely important.  Some solvents absorb through the skin more than others and some are dangerous by themselves.  One of the worst is xylene and vinegar is probably the safest for cleaning epoxy off skin.  Acetone is quite safe and is the major ingredient in nail polish remover.  It does overly dry skin and some find it irritating.  https://pubchem.ncbi.nlm.nih.gov/compound/acetone#section=Top

 

On another topic, I used a hole through the stem for my bow painter/tow line as Graham describes.  Bow eyes, like anchor rollers act like battering rams.  As I towed my Spindrift a lot this lack of feature was very appealing.  Having the origin of the tow line down a bit helps lift the bow while towing as well.  My hole was just above the bow compartment, but was low enough to work well.

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Reading more on this topic, I think I just want to put on some HDPE sacrificial strips and Xynole only where I'll likely to get abrasions from beaching it. Does this mean Xynole first then HDPE strips?

 

10 oz glass up to the waterline is probably not a bad idea if I take it somewhere rocky, and perhaps 4 oz on the inside bottom.

 

Should I glass before putting on the keel?  

 

What about epoxy-based undercoats for painting? 

 

Wear strips should be last, they are considered sacrificial and should be easy to replace.

 

10oz glass would be a good idea over the chines for impact resistance.  But everything is a compromise, add weight and strength or go for light?  Keep in mind that 10oz cloth is not very much glass and will not survive a good wallop on a rock.  I would put glass under my feet for additional wear resistance but that is a personal preference and not for the weight conscious.  Actually, I have looked into this and the densities of glass and resin are close enough that when a surface calls for 3 coats of resin only, I will always add 6 or 10oz cloth, there is no weight penalty to speak of.  There are some accounts of resin only coatings failing in freezing conditions.  The boat may not live in those conditions on build, but you never know where it's going to end up over it's long life.

 

Definitely glass the hull, then add the keel.  If you damage the keel the hull core remains water tight.

 

Epoxy undercoats are going to be the most expensive but probably the best performing.  I have used both single part (interlux pre-coat) and epoxy (alexseal 442 and 302 and others)  I like both and they both have their place.  If your top coat is 2 part then an epoxy primer is required.  2 part topcoat will be harder and more durable, therefore will show less wear under similar conditions.

 

Keep in mind that I run my stuff hard and sometimes make decisions that are not in the best interest of my equipment.  So I build with this in mind, erroring towards the tougher side rather than the light weight side.  When I build boats that would be used by less aggressive users and I would back off a bit.

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Thanks, Sean!(?)

 

I read through some more of Dave's posts earlier today and it looks like 10 oz glass and hollowback on the keel up to the stem and on the chines will work well.  I'll probably add 10 oz glass on the inside bottom.  

 

I intend to use a 2-part poly paint.  

 

I saw Alan add only 2 coats of epoxy on the inside tanks of his CS 15.  Another poster said that 3 coats are required for 10 mil thickness and even water-tight compartments can suffer build up condensation.  

 

I've noticed from riding epoxy surfboards that 8 oz glass on the deck can be dented even by feet over time when you stand up.  The plywood and epoxy seems like it gives the most hardness.  I hadn't considered the temperature factors you mentioned, though. 

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I haven't updated this in 10 days but I have been working on the boat.  I tacked in the transom and put in the quarter knees making sure I didn't force the hull out of fair.  After re-leveling the boat, checking again for twist as explained above, and wedging the longitudinal bulkheads into place with some shims, setting the partial bulkheads against the (masked) temporary center frame I tacked the hull together with thickened epoxy and a 3/8" filleting stick.  I really like using a frosting bag or a gallon ziplock bag filled with thickened epoxy and cut-open at the corner to apply fillets.  It makes it way faster than trying to scoop epoxy out of the pot and apply it with a filleting stick.  You have to work in smaller batches of epoxy when filleting with the frosting bag so that the epoxy doesn't kick-off, but so what?  

 

The kit goes together extremely well.  I have not had to plane any of the parts to fit them.  I learning a lot about boatbuilding without killing myself.

 

Next week I plan to pull out the wires holding the boat together, put in the outer seat cleat, and do a lot of sanding.

 

On the topic of sanding, I don't like doing it. I like Alan's method of applying the next layer of epoxy to the previous layer within the previous layer's cure window so that you don't have to sand the previous layer and the top layer of epoxy forms a chemical bond with the one underneath.  I plan on using three layers of epoxy on the inside compartments in case there is condensation. The questions are, "How long is the cure window?" and "Doesn't vary by temperature?"   

 

To tape long seams like the keel, should I use only one long continuous piece of tape or can I use several shorter ones?  DOes the keel line require only one layer of tape inside?

 

My EPS sheet foam epoxy box storage works really well.  I only need a 13 W lightbulb to keep it warm. 

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Progress has been slower since I went overseas for a week then entered the busy time of year for work.  Here's how she looks now:

post-5751-0-84471500-1477792755_thumb.jpg

 

Today I used the "two stick" method to scribe a line where the outer stringer should go.  Then I dry fit the seat stringers with drywall screw pads as clamps.  Monday, I'll glue them in.  

 

post-5751-0-59533200-1477792766_thumb.jpg

 

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Walt, I did the keel with one long strip and it wasn't difficult. As long as the pieces overlapped, and were wet out properly there is probably no reason you couldn't do it with a series of more pieces, but I don't think it would be easier. I always find the most difficult part of fibreglassing is dealing with the cut piece where the fibres are loose and spread out. If you do it with one long piece you minimise that part.

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I think I'm going to get the 6 oz 60" wide plain weave for the foils, the centerboard trunk, and the seats/floor and the 10 oz x 60" for the hull.  

http://www.fiberglasssupply.com/product_catalog/reinforcements/glass_fabrics/glass_fabrics.html

 

Has anyone used a bubble roller to roller out air bubbles from layup? 

http://www.fiberglasssupply.com/Product_Catalog/LaminatingTools/laminatingtools.html

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Use a squeegee. it removes bubbles, smooths the laminate, spreads the resin evenly, removes excess rein. Start with a "pool" of resin at one end and "drag" it around an area until the glass turns clear, then drag the extra resin onto the next area. There is a special rubber squeegee you can buy, but a plastic automotive "Bondo" spreader will work fine.

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The Gougeons suggest using "Surface Glazing."  The only type I could find was PU:

 

 

Surface Glazing
While primers don’t significantly reduce finishing time,
glazing or surface compounds often do. These commercially
available products are much thinner than standard
puttying fillers, so you can apply them quickly in a thin
film over large areas. We recommend using a wide
putty knife or squeegee to apply surfacer. This technique
results in a relatively smooth surface which is not difficult
to sand to a fine finish. Since small particles of dirt
can interfere with your finish, be sure your surface is
clean before applying these products.
Surfacing compounds have an advantage over primer
paints in that they are high solids materials and can be
used to mechanically force-fill small voids and depressions.
Imperfections in an overall cured epoxy surface
can be filled quickly and efficiently, assuming that they
are reasonably small or shallow. Often, the choice is
between sanding away small air holes and valleys or
filling them. The extra sanding takes time and may
involve the removal of more protective epoxy coating
than desirable, so surfacing compounds present an
attractive alternative.
All major paint companies market these compounds
with instructions for their use. Be sure to select compatible
surfacer and finishing systems since some finishes
use very active solvents which can lift surfacing materials.
Also check your instructions to be sure that you use
the recommended thinner when your compound is too
thick to apply in a controlled thin film.
Be particularly aware of the consistency of your glazing
compound as you apply it. If it is too thick, it will be
difficult to apply in a controlled film, and if it is too
thin, you will lose filling power. It’s better to err on the
thin side because you can always apply a second coat,
and this is much quicker than sanding away excess.
You may have to add thinner at regular intervals to
make up for its continual evaporation as you work.

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It sounds like you're adding a lot of weight with all that extra glassing you speak of. Like seats, floor and hull. Do you need to for abrasion resistance or something else.

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Guys,

 

Here's a discussion Alan and I had over email about glass and paint.  Glassing the hull is easier than taping, sanding the tape, and fairing.  Others may disagree.  Glassing the trunk is a faster way of building up the epoxy thickness.  I intend to glass the outside and centerboard trunk with 8 oz and forget about glassing the inside aside from the taping.  I'm leaning towards putting UHMW on the keel and stem and sacrificial plywood on the chines for abrasion resistance.  Fiberglass doesn't seem to add much meaningful abrasion resistance.  

 

 

I usually glass the inside of the trunk but Graham never has. I find that putting a layer of glass in there is just a faster way of ensuring that I get a nice even thickness of epoxy for sealing more than anything else inside the trunk. 

 

The biggest reason to glass the outside of the hull in my mind is to make building easier. The outside glass replaces the outside glass tape (because it's redundant to have tape and then glass over it) so you have the boat upside down and you sand it all smooth and fill in any voids in the gear chine and round over the corners then you lay glass over the whole thing and after it's fill coated to fill in the weave YOUR DONE. If you use glass tape then you have all of the edges of the glass that now need to be faired into the surrounding bottom and topsides with fairing filler and sanded smooth with the hull before the whole bottom is epoxy coated to seal it. So glassing the whole outside does both the glassing, sealing and fairing all in one step. For that reason alone i would glass the bottom with 8oz glass. Yes it will add some weight but you can also add weight by doing a bad paint job or making your fillets too big or by adding lots of hollow back! haha. Anyway I think it's a good tradeoff. 

 

I don't agree that epoxy only finishes would be at all effected by cold water use. I also don't agree that fiberglass will add much abrasion resistance at all. If you drag a fiber-glassed chine on a concrete ramp it's going to cut right through it in about 1 foot of dragging. You could add hollowback to the outboard most part of the bottom under the chine say about a 4-6' piece that would normally hit the ramp as the boat tips on edge just make sure the fasteners are well sealed which can be tricky since they are inside the seat tank. Adding screw type access ports would be a must so that you could inspect the tank and let it air out if any water got in. So now you have some hollow back and fasteners on both sides plus say 4 screw type access ports. That is starting to add weight too!!! Everything adds weight. 

 

You might consider simply gluing on a 4' long sacrificial piece of wood right under the chine outboard that will get chewed up if it gets dragged but since it's isolated from the hull would not damage the hull, it could be ground off and replaced if needed and sanded smooth if needed. No fasteners would be required and so no ports would be needed because the seat tanks would not be compromised. A couple of ports is still a good idea for jacket storage etc but at least you wouldn't worry about fasteners through the hull. 

 

Hollow back down the stem and keel is a good idea because it lets the boat bump over stuff in the water, nose up onto a ramp or beach and reduces wear on the forefoot which is a high wear spot. 

 

Graham typically leaves the bottom painted with epoxy primer which is easy to patch and sand nice and smooth but it is a bit soft and scratches easily so it's also a trade-off. I painted the bottom of my CS-17 with 2 part poly paint and it has also held up well. The best method for a smooth low drag bottom is to use a primer to make the surface even and a consistent color which make it easy to see any voids or lumps or bumps which can be sanded and smoothed before the final paint which may be just another coat of primer or a 2 part paint. 

 

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