Re: fg butt, is dishing necessary?
Hi guys,
My recommendation was for building smaller boats, using 1/4''
plywood. I used polyester resin to hold the butt together, and one
layer of 6'' tape. It's plenty strong, and the chines and gunwales
take most of the stress and punishment.
If I were going to build a boat using thicker plywood, implying a
bigger or tougher boat, I'd do the butts differently. I'd definitely
use multiple layers of cloth, cut on the bias, and (probably) epoxy
resin. I'd also dish out the plywood, at least on the exterior.
If the panel layout allowed it, without adding to the sheet usage,
I'd just scarf the panels together. It's just as easy as butting, and
all in all, probably takes the same amount of time. The techniques
are just different. I was surprised how easy scarfing is.
Take care,
Pete
My recommendation was for building smaller boats, using 1/4''
plywood. I used polyester resin to hold the butt together, and one
layer of 6'' tape. It's plenty strong, and the chines and gunwales
take most of the stress and punishment.
If I were going to build a boat using thicker plywood, implying a
bigger or tougher boat, I'd do the butts differently. I'd definitely
use multiple layers of cloth, cut on the bias, and (probably) epoxy
resin. I'd also dish out the plywood, at least on the exterior.
If the panel layout allowed it, without adding to the sheet usage,
I'd just scarf the panels together. It's just as easy as butting, and
all in all, probably takes the same amount of time. The techniques
are just different. I was surprised how easy scarfing is.
Take care,
Pete
--- In bolger@y..., wade@l... wrote:
> Hello,
>
> Mud season is underway here in the Finger Lakes, and I'm getting
ready to start my Clam Skiff. (Will decide about the cabin after I
build the skiff part.)
>
> Dynamite Payson's contruction notes (from National Fisherman mag)
say to make the sides using fiberglass butts.
>
> I remember seeing some comments in this discussion group to the
effect that you can dispense with pre-dishing at the edges to be
joined, and the extra thickness of the fiberglass won't be terribly
noticeable.
>
> Does anyone have direct experience or recommendations in this
regard? I'm hoping to end up with a finish in the ten-to-twenty-foot
range.
>
> Thanks
>
> Wade Leftwich
> Ithaca, NY
The wax paper is not such a good idea as the wax can interfere with further epoxy or paint.
The trash bag is good, but I have found a thicker piece of poly, say 10 mils, is easier to smooth out and leaves a no-wrinkle finish.
Currently my favorite fiberglass-ply butt joint is;
Router out enough of the ply to almost the thickness of the cloth x the width of the cloth. Cut this cloth on the bias, so every thread crosses the joint. Pre wet the ply end grain and routed sections of ply and wet the cloth on a scrap of plastic. With a bit of thickened epoxy added next, butt the ply, lay down the wet cloth, add a bit of epoxy thickened with an easily sanded filler, then a layer of peel ply smoothed with a flat stick, a layer of 10 mil poly, a smooth scrap of ply, and some weights. Next day repeat on the other side.
With only a minor bit of filling and sanding the result is an invisible butt joint.
Rick
I used an opened up
> trash bag instead of waxed paper.
I have read guys talking about 'peel ply.'
Airplane dacron fabric (for covering) can also be used instead of peel
ply, at least if you are working on top of something strong like
plywood. The idea of peel ply is to leave a textured surface that's
easy to glue to without sanding, and also to allow excess epoxy to
bleed out. Doesn't seem necessary for a fiberglass butt.
I think mat is only for use with polyester, in general. Has stuff in
it that's incompatible with epoxy is what I've heard.
ply, at least if you are working on top of something strong like
plywood. The idea of peel ply is to leave a textured surface that's
easy to glue to without sanding, and also to allow excess epoxy to
bleed out. Doesn't seem necessary for a fiberglass butt.
I think mat is only for use with polyester, in general. Has stuff in
it that's incompatible with epoxy is what I've heard.
--- In bolger@y..., cha62759@t... wrote:
>
> Yes, available from WEST system (among other I suppose.) But wax
paper
> serves very nicely indeed. I believe the peel ply whatever it's name
> is is really for more intricate procedures. For your purposes clean
> visqueen or wax paper are fine. Mr Payson uses mat in his fiberglass
> butt which should be stronger than just the fiberglass cloth but
again
> unless you're really stressing a butt joint cloth should be just
fine.
>
>
> > I have read guys talking about 'peel ply.' Is peel ply a
commercial
> > product sold for this purpose?
> >
> > Peter
Yes, available from WEST system (among other I suppose.) But wax paper
serves very nicely indeed. I believe the peel ply whatever it's name
is is really for more intricate procedures. For your purposes clean
visqueen or wax paper are fine. Mr Payson uses mat in his fiberglass
butt which should be stronger than just the fiberglass cloth but again
unless you're really stressing a butt joint cloth should be just fine.
serves very nicely indeed. I believe the peel ply whatever it's name
is is really for more intricate procedures. For your purposes clean
visqueen or wax paper are fine. Mr Payson uses mat in his fiberglass
butt which should be stronger than just the fiberglass cloth but again
unless you're really stressing a butt joint cloth should be just fine.
> I have read guys talking about 'peel ply.' Is peel ply a commercial
> product sold for this purpose?
>
> Peter
> I say almost, because I used an opened upI have read guys talking about 'peel ply.' Is peel ply a commercial
> trash bag instead of waxed paper.
product sold for this purpose?
Peter
Wade:
I agree almost totally with Pete. I say almost, because I used an opened up
trash bag instead of waxed paper. Other than that, we agree completely. I
might add that I have done it both ways, and once I did it without the cove,
I never went back.
Chuck
I agree almost totally with Pete. I say almost, because I used an opened up
trash bag instead of waxed paper. Other than that, we agree completely. I
might add that I have done it both ways, and once I did it without the cove,
I never went back.
Chuck
> Wade,
>
> I built my Surf using fiberglass butts. I didn't bother to hollow
> out the area, and they blend in well with the topside, once finished.
> Once I had the tape down, and saturated with resin, I layed a piece
> of wax paper over the whole joint. Then I took a squeegee, and
> smoothed out the resin. This squeezed out some resin past the tape
> borders. Once cured, the wax paper came off easily, and there was a
> smooth, faired ramp of resin sloping up to the tape edge. The butt
> stood out like a sore thumb, but it soon disappeared.
>
> I spent a little extra time sanding the butts when I got to the
> painting point. I kept running my hand over them to make sure the
> transition was pretty smooth. Then I painted with two coats of Kilz
> water-based primer, and two coats of semi-gloss latex porch paint.
> The finish came out much better than a 10' paint job. I'd say it's
> more like a three footer.
>
> Take a look at the folder "Surf's Up" in the Files section. The
> blue Surf is mine (another guy added photos of his gorgeous Surf to
> this folder - his is red). The side shots of the boat were taken from
> about 15-20' away. I know where to look for the butts, but no one
> else has been able to see them. My boatyard is shady, but the butts
> still don't really show in bright sun.
>
> Dishing the butt area will enable you to put a really smooth
> finish on your boat. I went with the drywall theory: spread the mud
> out far from the joint, and sand the ramp smooth. Less fussy, I think.
>
> I hope this helps.
>
> Take care,
> Pete Reynolds
>
Wade,
I built my Surf using fiberglass butts. I didn't bother to hollow
out the area, and they blend in well with the topside, once finished.
Once I had the tape down, and saturated with resin, I layed a piece
of wax paper over the whole joint. Then I took a squeegee, and
smoothed out the resin. This squeezed out some resin past the tape
borders. Once cured, the wax paper came off easily, and there was a
smooth, faired ramp of resin sloping up to the tape edge. The butt
stood out like a sore thumb, but it soon disappeared.
I spent a little extra time sanding the butts when I got to the
painting point. I kept running my hand over them to make sure the
transition was pretty smooth. Then I painted with two coats of Kilz
water-based primer, and two coats of semi-gloss latex porch paint.
The finish came out much better than a 10' paint job. I'd say it's
more like a three footer.
Take a look at the folder "Surf's Up" in the Files section. The
blue Surf is mine (another guy added photos of his gorgeous Surf to
this folder - his is red). The side shots of the boat were taken from
about 15-20' away. I know where to look for the butts, but no one
else has been able to see them. My boatyard is shady, but the butts
still don't really show in bright sun.
Dishing the butt area will enable you to put a really smooth
finish on your boat. I went with the drywall theory: spread the mud
out far from the joint, and sand the ramp smooth. Less fussy, I think.
I hope this helps.
Take care,
Pete Reynolds
I built my Surf using fiberglass butts. I didn't bother to hollow
out the area, and they blend in well with the topside, once finished.
Once I had the tape down, and saturated with resin, I layed a piece
of wax paper over the whole joint. Then I took a squeegee, and
smoothed out the resin. This squeezed out some resin past the tape
borders. Once cured, the wax paper came off easily, and there was a
smooth, faired ramp of resin sloping up to the tape edge. The butt
stood out like a sore thumb, but it soon disappeared.
I spent a little extra time sanding the butts when I got to the
painting point. I kept running my hand over them to make sure the
transition was pretty smooth. Then I painted with two coats of Kilz
water-based primer, and two coats of semi-gloss latex porch paint.
The finish came out much better than a 10' paint job. I'd say it's
more like a three footer.
Take a look at the folder "Surf's Up" in the Files section. The
blue Surf is mine (another guy added photos of his gorgeous Surf to
this folder - his is red). The side shots of the boat were taken from
about 15-20' away. I know where to look for the butts, but no one
else has been able to see them. My boatyard is shady, but the butts
still don't really show in bright sun.
Dishing the butt area will enable you to put a really smooth
finish on your boat. I went with the drywall theory: spread the mud
out far from the joint, and sand the ramp smooth. Less fussy, I think.
I hope this helps.
Take care,
Pete Reynolds
--- In bolger@y..., wade@l... wrote:
> Hello,
>
> Mud season is underway here in the Finger Lakes, and I'm getting
ready to start my Clam Skiff. (Will decide about the cabin after I
build the skiff part.)
>
> Dynamite Payson's contruction notes (from National Fisherman mag)
say to make the sides using fiberglass butts.
>
> I remember seeing some comments in this discussion group to the
effect that you can dispense with pre-dishing at the edges to be
joined, and the extra thickness of the fiberglass won't be terribly
noticeable.
>
> Does anyone have direct experience or recommendations in this
regard? I'm hoping to end up with a finish in the ten-to-twenty-foot
range.
>
> Thanks
>
> Wade Leftwich
> Ithaca, NY
Hello,
Mud season is underway here in the Finger Lakes, and I'm getting ready to start my Clam Skiff. (Will decide about the cabin after I build the skiff part.)
Dynamite Payson's contruction notes (from National Fisherman mag) say to make the sides using fiberglass butts.
I remember seeing some comments in this discussion group to the effect that you can dispense with pre-dishing at the edges to be joined, and the extra thickness of the fiberglass won't be terribly noticeable.
Does anyone have direct experience or recommendations in this regard? I'm hoping to end up with a finish in the ten-to-twenty-foot range.
Thanks
Wade Leftwich
Ithaca, NY
Mud season is underway here in the Finger Lakes, and I'm getting ready to start my Clam Skiff. (Will decide about the cabin after I build the skiff part.)
Dynamite Payson's contruction notes (from National Fisherman mag) say to make the sides using fiberglass butts.
I remember seeing some comments in this discussion group to the effect that you can dispense with pre-dishing at the edges to be joined, and the extra thickness of the fiberglass won't be terribly noticeable.
Does anyone have direct experience or recommendations in this regard? I'm hoping to end up with a finish in the ten-to-twenty-foot range.
Thanks
Wade Leftwich
Ithaca, NY
Most mat is for use with polyester, but if you ask most suppliers will have mat for epoxy use
HJ
HJ
>% Harrywelshman@...
> I think mat is only for use with polyester, in general. Has stuff in
> it that's incompatible with epoxy is what I've heard.
> --- In bolger@y..., cha62759@t... wrote:
> >_ _ _ _ _