My Official build thread. 27 1/2’ GA

[Djeffrey]

I am using a 16 inch by 2 3/4 inch two handed block I got off amazon. Hook and loop sandpaper. I like the hook and loop because it seems to hold paper solid. I just ordered a flexible one for curves, same paper. I am using microballoons for fairing, sands fast.

[Brian.Dixon]

So, as fairing is in full swing what is the preferred long board?  Air, is there a electric one?   What’s everyone else using?

The point of a long board is to a) be flexible so it'll follow the natural curves of the boat, and b) it's long enough to span typical humps and hollows in the surface of the boat.   I have not seen any commercial answer that I like as well as the one that I made for myself.  First ... go down to your local auto body repair supply house (or online) and see what type of sticky-back sandpaper they have.  It'll come in rolls and will typically be around 3" wide.  That's how wide you make your long board.  The length should be about 24" to 26" long.  Cut it out of 1/4" plywood.  Add 3/4" dowel handles, on end, one about 2" from either end of the long board.  I glue and screw it in place, screwing from the back (sandpaper) side, counter sinking the screw so it won't stick up under the sandpaper.  I added a small fillet of epoxy around the base of each handle to strengthen it up.

I long board by sanding horizontally first, then at a 45-deg angle up one way, the at a 45-deg angle up the other way (the two 45-deg angles are 90-deg apart from each other).  The primary sanding is the horizontal direction and this will reduce your work when sanding at the 45-deg angles.  Don't make things absolutely perfect ... This is one of those 80% rules ... work beyond that won't show in the final paint.

Brian

[Rbob]

Yes you can make your own just how you want, paper is 2 3/4" wide.  I prefer the hook and loop so I bought industrial strength hook and loop off of Amazon a 15ft roll for $17.  You only need one side for the sandpaper.


You can buy hook and loop sandpaper in rolls also so if you make a non-standard board it will work perfectly or cut up the 16 1/2" to make it work.

The reason I like hook and loop is you can re-use the paper or switch between grits easily, if the sticky stuff gets dust on it, no stick no more!


For fairing I like #60 and switch to finer grit (150 -220) before priming  but for sanding primer you don't want the HD and they make almost any grit you need.

Amazon is where I purchased the Mirka Abranet, it is screen type roll, not solid backing.. blows out easily, less clogging.   

[Todd j]

Soo, are you getting both sides of the hook and loop so you can attach one side to your custom board?

[Rbob]

Yes, sir!  Its is a super sticky adhesive so line it up good before you lay it on your board and press it down firmly / use a roller to attach.  It does not come off.

[Todd j]

I was confused because what you posted looks like open mesh.  I looked at several boards on Amazon and didn't see the abrasive that went with.  I can make my own with al the stuff ifi get it right. 

[Rbob]

Todd,

The sandpaper is open mesh Velcro backed.
https://www.amazon.com/s?k=mirka+abranet+roll&ref=nb_sb_noss_1

You can buy the durablock hook and loop block up to 48"  (4.5" wide), rigid and flexible. check ebay also. They get $$ which is why I made my own.  You can get 4.5" sandpaper also.

https://www.amazon.com/Dura-Block-AF4419-Black-Sanding-Block/dp/B003M5UK14/ref=sr_1_4?keywords=durablock+velcro+block&qid=1561652829&s=gateway&sr=8-4

https://www.dura-block.com/Hook-Loop-Blocks_c_20.html

I dont reccomend 4.5" wide paper / blocks unless you have two people to operate the 36 - 48" sanding board (misery whip), made me whine like a little girl.


I made a block with 2 rows of velcro and can use to strips of 2 3/4" paper which is a lot cheaper than the 4.5" paper.  It is a beast to use.

[Todd j]

That was very  helpful.  Thx.  Think I'll try it

[Todd j]

Started some more taping between sanding sessions.  Any tips for taping outside corners?   I taped the fairbody and it kicked my ass.  I could not seem to get the tape to lay down tight and flat to both sides of the keel on the knee.    I think I’m going to have to try to inject some epoxy in there.  Pain in the butt. 
   I did install my two new wen air filters.  It’s amazing what’s in the air even when your not making dust.  If you don’t have one or two in your shop I think you should get some.  I bought two small ones for a 20x30 shop.   Healer than 1 bigger one.  The remote controls both units simultaneously so that’s cool

[Brian.Dixon]

Started some more taping between sanding sessions.  Any tips for taping outside corners?   I taped the fairbody and it kicked my ass.  I could not seem to get the tape to lay down tight and flat to both sides of the keel on the knee.    I think I’m going to have to try to inject some epoxy in there.  Pain in the butt. 
   I did install my two new wen air filters.  It’s amazing what’s in the air even when your not making dust.  If you don’t have one or two in your shop I think you should get some.  I bought two small ones for a 20x30 shop.   Healer than 1 bigger one.  The remote controls both units simultaneously so that’s cool

The best fiberglass tape for taping seams around hard bends is .... homemade glass tape.  You cut it out from standard woven fiberglass cloth.  You cut the tape at a 45-deg angle to the weave.  When applying the tape to the seam, the yarn crosses the seam at a 45-degree angle.  This effectively reduces the sharpness of the bend in the direction of the yarn and the glass lays down a lot easier.  With a wheel cutter and metal straight edge (yard stick), you can create your special tape pretty fast.  When applying it, you'll have stragglers of glass along the edges on the boat ... ignore that and just get the glass wetted out.  Use your carbide scraper after the epoxy cures to slice off and smooth the stragglers.

Brian

[Todd j]

I checked it this morning and it looks better than I let on.   I don’t think it’s going to take anything extra.  Will gave another look when I get home this weekend. 

[Todd j]

I just emptied my second 5 gallon bucket of epoxy.  Those big flat panels sure are thirsty. I ordered up a durablock and some paper/mesh.  I have one hollow that is taking a fair amount of filler.   The scarfs did not take hardly any filler to make them fair. 
  I finally cut the extra plywood off the transom and the sides of the boat.  I couldn’t find a pullsaw so I used my trusty reciprocating tool.  This tool is another one I bought for a not boat related project, but has found its way into the boat barn a couple times.  I’m not sure how I lived this long without it!
  A couple weeks back I posted a hand drawing of a swim platform idea. For swimming/diving and getting back into the boat.  It used the stringers as supports.  I left the top(away from the water) 3” still on the boat.  I figure I can add a 1 1/2” back to the top to get further away from the water.  I welcome any thoughts on pursuing this design. 

[Brian.Dixon]

Looks like that should work for the swim platform.  Just to make it pretty, but also help with loads, I'd add some curvy knees on the bottom of the extensions in the bottom corner where they come out of the transom.... more boaty and more stronger

Brian

[Todd j]

Good idea.  I was concerned about “stuff” too close to the bottom

[json]

That's a cool idea for the platform, I am looking forward to seeing how that turns out. Does your 27 1/2' include the platform or is that going to be in addition?