Petrel Deck Alignment

Hi.  first Build and going ok so far.  Until today.  Did a dry fit of putting the deck on the hull.  Stern is taped and looks like a good fit.  Cockpit area is close and was able to tape it in place with a little help from a putty knife pushing and pulling.   But when I got to the front hatch area the Deck over hangs the hull about  1/2 to 3/4 inch per side.  I pushed the hull and got it to move with some force but cant keep it there with tape.  Deck seam to have little give or movement.

I keep the forms in place as I glassed both the hull and deck as instruction stay. Both hull and deck are both a little out of alignment to the forms now.

Hull has glass inside and out with second layer of glass on bottom and wrapped 1inch over the chimes and fill coat.  Deck has glass on inside only with fill coat.

So my thought was to drill a couple of holes on each side of the hull & deck and stitch it.  Once I tape the  inside seam and it dries then I can remove the stitches.

Any suggests would be appriecated.


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RE: Petrel Deck Alignment

   Dont know if matters...but this is a Pretel play SG

RE: Petrel Deck Alignment

Hi Saltirose, 

i have not built the petrel play stitch and glue, but i have had similar issues on other builds.

so what i usually find, and its not totally clear to me based on your description, is that decks and hulls tend to widen out and then, as you say, get challenging to align.

one trick i have used when strapping taping from the outside does not create enough pressure to pull the hull and deck into alignment is to use strapping tape (i always use fibreglass filament tape becuase it does not stretch), across the hull or deck to pull it into the right dimension.  the picture below is a hull i am building right now and the strapping tape you see across the bottom is holding the deck in alignment to where the forms would have it if it was sitting perfectly where it should be.

then when i need to actually attach the deck to the hull, i kept this tape in place and then did the usual strapping tape on the outside to pull the hull and deck together (see picture below).

most of the tape is on the outside, but you can see that the blue marked tape was 6 pieces across the bottom of the deck to get it to line up (in this boat the deck flattened a lot after it came off the forms relative to the hull).

then, i went inside the boat and tacked the hull and deck together with cabosill/epoxy mixture working around the 6 blue tapes.   once that cured, i removed the 6 blue tapes and everything was now nicely in alignment and then i epoxy and fibreglass taped the inside as normal.

anyway, it worked very well.....stitches would have probably worked too....but i found this approach pretty easy and straightfoward and did not have to make any extra holes.  

hope that helps


RE: Petrel Deck Alignment

I have just started a Petrel Play SG build and was wondering about getting the deck and hull to match. It seems to me that if they don't fit well it stresses the fiberglass/epoxy when they are pulled together, potentially weakening the structure.

I was contemplating building the hull and deck and checking their fit before doing fillets and fiberglass. I'd use packing tape to pull each unit into the necessary shape for glassing.

Thoughts/recommendations are welcome.


RE: Petrel Deck Alignment

Your idea is sound and i routinely use the techniqe you describe.

the more you tightly control the alignment during the build process, the easier it will be when you get to the 'hull-deck mating' step.

as you surmized, mating the hull/deck when the underlying panels were not even glued in the right position can be particularly challenging. 

i would also suggest that in addition to ensuring you glueup your panels with the proper alignment, even after the glue is cured, keep the strapping tape on to hold things in their design shape.  there are other forces that can make a hull diverge from its original shape humidity (especially when one side is glassed/or covered with epoxy and the other side isn't).  the wood will also naturally want to 'relax' into a shape that can diverge from the design.   even cutting hatches and the reinforcement around hatch openings can bend a deck out of its intended shape.

so when i build, per the previous post, i am usually doing something to hold everything in alignment right up to the time i am mating that hull and deck.

that said, my analysis is that bending stuff does not typicall make anything 'weaker'.  but at some point, if you apply enough pressure, you will simply crack the piece.....and then there is a lot of unhappiness.  it's also just very difficult when you are working so hard to bend a piece....other mistakes tend to happen when a lot of pressure is involved.   so its best to be careful and not put yourself in that position.



RE: Petrel Deck Alignment

   Thanks for the tips. The hull is stitched and I've put it aside until I get the deck assembled. I noted that the hull sheer line runs pretty straight from the stern form (#4) to the next form (#3) on both sides. With the deck assembled I'll be able to determine if it is supposed to have some curve.

The bevel where the upper side panels meet the lower side panels near the stern abruptly stops, leaving a 1/16" gap between the panels. The last 6 inches of the panels have a square edge so there's no way short of sanding/planing them to take out the gap. I'm planning to tape over this gap when I do the fillets. there's a similar but smaller gap at the bow.

Everything is mating well and I'm satisfied with how it has come together.

RE: Petrel Deck Alignment

"   Deck over hangs the hull about  1/2 to 3/4 inch per side.  I pushed the hull and got it to move with some force but cant keep it there with tape. "    Sure my stripper was 2" to 3"  off.  My two, deck and hull, were apart too long.   

I used a 2x2 strut the right length to push the hull out . Then used strapping reinforced packing tape {lots of tape}  with occasional ratchet straps to pull the deck in so it could be taped........lots of tape long pieces. Note you have to sneak up on the overhang a little at a time for a long way progressively.   

You would of course roll out reinforcing tape on the inside first. Then when fully cured do the other inside side then the outside joints. The strut comes out once the outer tapping is secure..........lots of tape. 


RE: Petrel Deck Alignment

   Here's what Nick has to say...

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