Skin Stitch and Sealant combo

[Bzonic]

Hello all – I’ve read Jeff’s book and just about every page of these forums so I feel pretty good about the Curlew endeavor I’m about to undertake.  The one thing I’m noticing as I digest all the good info here and in the books is that there seems to be an evolution of technique/materials used as better methods and materials become identified.  While it’s great for that to be occurring it does leave me with some indecision as to the best approach to take for my materials choice.  I’m wondering if I can get some opinions on my approach.  My goal is to have a really durable and tight skinned boat so I’m using the 11 oz poly skin, Dura tuf for sealant, and the double cord stich method from Jeff’s video.  Please chime in if you think I will encounter any problems with this combination.  Thanks!

 

Brian in Cleveland OH

[NY_Rocking_Chairs]

Brian,

 

I just built a Curlew using the 11-ounce and the double corded stitch.  I didn't run into any major problems and the DCS looks really nice.  The 11-ounce will not shrink very much (I used a heat gun and IR thermometer) so try and pull it as tight as you can during the stitching., but the fabric is tight enough that you can really crank down on the stitching without worrying about the weave opening up.  I found that keep the cords about 1" to 1 1/4" apart when initially stiching and then pulling tight was just about perfect for pulling the skin tight without opening up the weave.

 

One thing that I found is that stitching from the cockpit outwards I was able to follow the top-center spar as a good guide to keep the stitch centered on the boat.  However, that spar doesn't run the entire length of the boat and I found my stitch getting off-center, so I backed it out and taped an extra piece of wood in place to keep a center reference, then pulled it out once I got to the bow and stern plates.

 

I used Rustoleum as the sealant and have no experience with the Dura Tuf so cannot comment on that.

 

Good luck.

-Rich

[Bzonic]

Thanks Rich - I will be definitely be coming back to your tips when I'm ready to sew.

[Kudzu]

What he said! 

 

Dura-tuff is a good finish. I have not tried it (yet) but I don't see any reason it can not be tinted if you want color. It is water clear out of the can.

 

But paint is also a good finish. I paint nearly all my boats and it easy to touch up too.

 

I am working on reskinning my canoe and I have seriously thought about a military style camo paint job. Since those are flat colors they will seep water most times. so I have been thinking about spraying Dura-tuff over that.

[Bzonic]

Ok great - if I don't plan to skin the boat for several months should I go ahead and place an order sooner than later due to the skin material drought mentioned in the other thread?  Sounds like you are investigating so new materials that have much potential but if you think the 11 oz poly is a very good choice I will get some now from you.  Thanks again!!

[Kudzu]

I have 150+ yards in stock. I don't see much chance of it running out.

[mfrankel]

Dura Tuff

 

The good:

 

I used dura tuff on 8 oz polyester skin on a rowboat.  It is as clear as water.  I used it un-tinted and it looks fantastic.  The light glows through the fabric.  The stringers are clearly defined through the skin.  It is exactly the look I was going for. 

 

The bad:

 

It is either more vulnerable to seepage than Rustoleum paint, or I can't figure out how much to use or how to properly apply it.  It is like liquid plastic.  I put quite a few layers on already using a 6" foam roller.  It may be that it does not go on adhere well enough with a foam roller. I bet it should be sprayed, but i did not try that.

 

It sets up very quickly so you can't go back over it much.  The fumes smell toxic. It is not exactly use friendly. 

 

I lost count but I have probably applied more than 6 thin coats and I still get about 3/4" of water in the middle of the boat along the keel after an hour or 2 on the water.  That is acceptable.  I have a small can left so will probably add another couple of coats at the beginning of this season.  Maybe that will finally seal it.

 

The bottom line:

 

If you want a crystal clear finish for a relatively see through look, (or as see through as you can get with 11 oz material), use the Dura Tuff.  It takes a lot more effort but it looks fantastic with no amber tint like varnish leaves behind.

 

If you want to use Dura Tuff because your research tells you it is better than paint or varnish, you may be right,  Unfortunately, there is almost no guidance on the web for how you apply the stuff to polyester.  Paint is almost idiot-proof and predictable.

[Hirilonde]

Paint the whole boat in gloss of the primary color before the camo Jeff.  That should seal it before you add the other color blotches.

 

[Kudzu]

mfrankel - Put the boat on saw horses, add 1-2 gallons of water and see where the water is coming in.... in this case going out of the boat. It may not be the Dura-tuff but may be that  you have seam leaking. Either way you will find the leaks fairly quickly. 

[Bzonic]

Thanks for the heads up on the potential for grief during the application process.  I'm curious if you have an isolated leak area as well.  I really like the translucent look and your confirmation of how good it looks makes me think I will stick with my plans to use the Dura Tuff.  I don't know what a readily available runner up would be anyway. 

[Kudzu]

Another good method to check how well you coverage is, is to put a light inside the boat and look for pin holes. Of course this will probably not work as well with a clear finish, but it works great with paint. After 2 coats with paint you will see lots of pin holes of light (with the 8 oz.). While I haven't tried it, I suspect 2 coats will work on the 11.5 oz.

 

I suspect Dura-tuff is hard to roll or brush on because it is clear. There is little indication of how evenly you are applying it  so you have to be very consistent. I would imagine it would be very easy to have spots that were not well covered. I sprayed my VARDO and I don't think I had any problems with it.

[mfrankel]

Jeff: 

 

I tried the light inside the boat method because I had success with paint using that method.  I could see no pinholes with Dura Tuff.  I will try the sawhorse method when the season starts. 

 

If I had it to do over again, based on your success with Vardo, I would spray.