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Fairing The Hull

PostPosted: Sun Dec 10, 2017 10:59 pm
by r2heisch
Hey folks, need some suggestions please. So I worked most of my low spots on the hull using West 410 and got it looking fairly fair. I covered the hull with S2 glass which went on very well. Some prior blogs had mentioned how the glass really brings out the unfairness of the hull, but I was very please and must have done a decent job with my fairing up to this point.

So now I am at the stage of filling the weave and leveling off the areas where I had to overlap the glass. I an experimenting with both West 407 and West 410 for this procedure. I have tried mixing different amounts of the 407, trying varying consistencies. It seems like the 407 is much harder to sand than the 410 so now I am back to trying the 410. I have tried using different trowels but can't seem to get it to go on smooth, probably just my inexperience. I can't seem to even the get the weave to fill consistently with thinner material. (Seems to me that filling the weave should be a simple process...)

It also seems to take forever to mix the filler and epoxy and then it doesn't go very far. Maybe I should try and use a different filler? This whole process is getting frustrating!!

Re: Fairing The Hull

PostPosted: Sun Dec 10, 2017 11:20 pm
by Warren Nethercote
I used System 3 Quik Fair which goes on easily and sands easier than West stuff too. There are cheaper equivalents sold through people like Defender Industries or West Marine I think, but never use auto-body fairing compound because it contains talc, which absorbs water. A common shortcut is to do initial fairing with a notched trowel. The ridges are easy to get fair, then you fill in the grooves. It is too late now, but if you apply peel ply on top of the wet glass the weave gets filled with resin during lay-up and fairing to improve surface texture is much easier.

(Edit: PS. The process IS frustrating. Building upside down over FULL conventional framing might allow you to build without glass sheathing at all, and get away without fairing. Stitch and glue construction gives you quick early progress but generates extra effort as you fair out the tape and glass sheathing overlaps. My conventionally-built OK Dinghy was fair from the get-go. Sand and paint ...)

Re: Fairing The Hull

PostPosted: Tue Dec 12, 2017 4:35 pm
by admin
Hi r2, I used both WEST products, too. 410 is the easiest to fair, and it's cheaper. I think 407 feathers out easier, if I remember correctly. The deal is: the more 410 (or 410) you add to the mixture, the easier it is to sand. Sometimes I would add a slight amount of either just to change the color a little so that I could identify which layer was new/old.

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Depending on where I was working, I used plastic trowels of different lengths, and even an old silk-screen squeegee for larger, flat areas like the bottom. I didn't bother obsessing about how smoothly the mud was going on. Most of it was coming off anyhow (I even recycled some of the dust one day when I was suddenly caught with no filler -- probably not a great idea but worked in a pinch)

Bottom line is: the longboard is going to be your friend...or worst enemy by the time you are ready to throw some paint on it :-)

Re: Fairing The Hull

PostPosted: Tue Dec 12, 2017 8:45 pm
by r2heisch
Thanks guys! I probably just needed to vent some. I am really looking forward to getting past this...

Re: Fairing The Hull

PostPosted: Tue Dec 12, 2017 9:03 pm
by Tim Ford
HAH! totally understand that! (see "Help a brother out" thread from April 15, 2013 - back on Page 5 of Building an i550) I was so sick of fairing by that time I was ready to wrap the hull in ferro-cement and call it done.

On the other hand, there is a sort of Zen aspect to doing the longboarding. It's possible to get into it...takes a bit of attitude adjustment and a case or three of beer :-)

I've forgotten where you are, but if you are in the USA and want a free longboard and a roll of PSA sandpaper, let me know (shoot me an email: webwolf AT nbayracing DOT com)

--TF

Re: Fairing The Hull

PostPosted: Wed Dec 13, 2017 9:05 pm
by r2heisch
Thanks Tim but I actually made a couple that work pretty good. Then I bought an air powered one but had to increase the flywheel size on the compressor so it could push it. I'm using those interchangeably which does help.