Taping Seams on Shearwater Sport

I am just preparing to tack the seams of my Shearwater Sport. I notice a lot of light showing through the seams, so I am starting to tape the seams on the outside. I'm just wondering what the best product is to use for this purpose? Clear packing tape, masking tape, or something else?

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RE: Taping Seams on Shearwater Sport

When I build my Shearwater Double, I did not tape the outer seams during the tack weld process.  Your "drip-through" will be minimal as long as your epoxy/wood flour mixture is appropriately thickened.  (A tip here is to add a bit of Cab-o-sil to the epoxy mixture.  It will make the mixture more smooth and easy to spread.)  It is easy enough to get rid of any drips later when you sand the exterior.  You can use a file/rask to knock off the big globs then sand smooth.     

If you definately want to tape the outer seams, clear plastic tape is a good choice.  I have used it on the outside of the hull/deck joint during the mating process several times.  The trick is to make sure that the tape is perfectly smooth.  If it is not, and wrinkles will fill with epoxy which makes a big ridge to sand/file off.


RE: Taping Seams on Shearwater Sport

for pulling the deck and hull together (the tape that will be perpindicular to the seam) i use glass-reinforced packing tape.  this is the packing tape that has fibreglass fibers in it (looks like stripes) and it has almost no stretch.  i really tend to 'muscle' this step to get as tight a joint as possible.   another pair of hands can be really helpful here.   

once i have that step completed, i then run a piece of regular packing tape along/on-top of the seam to prevent drips and spills.  as mark mentioned above, you want to apply this tape with a bit of care to ensure it's smooth.

in general, the mixture, that i use for seaming, while tickened (with cabosil), is still pretty liquidy (syrup consistency) compared to creating a fillet....so my perspective is preventing drips and spills is something i think about. 


RE: Taping Seams on Shearwater Sport

One thing to remember when using tapes: removal may be tricky, depending on the adhesive quality of the tapes used and their affinity for the top veneer layer’s wood grain, particularly at edges.

Pulling tape off perpendicular to the veneer surface is to be avoided! Try to pull tape off as best you can by folding it back against itself then pull slowly, keeping tape removed in close proximity to tape being removed - 180° is the idea.

Should you encounter veneer adhering to tape, you can employ one of those plastic squeegee things used for smoothing epoxy, or a plastic putty knife, to put modest pressure on the tape just where it’s being pulled away from the veneer underneath. This helps minimizing tear-outs by lending some support to the veneer underneath as tape is ‘rolled off’ from above.

And go slow when you work near edges; best to pull away from them rather than toward.


RE: Taping Seams on Shearwater Sport

A bit of heat from a hair dryer or some such to warm the tape up as you go may help, as well.


RE: Taping Seams on Shearwater Sport

my advice re tape and avoiding pull out is to use a good brand like scotch and organize your work such that the tape goes on and comes off relatively quickly  (e.g., one day to tape it all up, one day to seam it, one day for full hardening and remove the tape the next day)

to the extent i have experienced problems, it also seemed to be related to leaving the tape there for extended periods of time (most tape gets 'funky' when left in place for a long time) or an offbrand tape that leaves residue.  


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