I have a WaterTender polyethylene rowing dinghy that has developed a
leak at the bottom of the keel. I've tried patching the leak with
epoxy, which works for a while, then starts leaking again. Can this
boat be saved?
If it's time to get a new dinghy, I've been looking at the Walker
Bay 8 polypropylene dinghy. Has anyone had any experience with this
15 Feb 2000
Patching polyethylene - ouch! I believe there is a sealant or
adhesive product made by Loc-Tite Corp. that is supposed to bond to
polyethylene. I'll look up the product code tomorrow at work and get
back to you. I would take some polyethylene sheet stock and make an
inner and outer patch considerably larger than the hole. I would
attach the patches to the dingy using closely spaced aluminum pop
rivets with washers and using this Loc-Tite sealant product in
between the inner and outer patch and the hull. If this patch ever
wears out, you could drill out the pop rivets, peal off the worn-out
patch and install a new one.
S/V Dynamic Equilibrium
16 Feb 2000
The Loc-Tite product that will bond to high-density polyethylene is:
||Loc-Tite Product Code|
|Primer 770||18396 for 1 fl oz|
|Loc-Tite 401||40140 for 20 g.|
Any industrial plastics distributor will probably be able to sell you
Loc-Tite products. Loc-Tite makes about 75 different flavors of
specialty adhesives. You won't believe what they will charge you
for these two tiny bottles of juice! But, this stuff works as
advertised and the small bottles will probably be sufficient to do
your job unless the area of the patches is several square feet each.
Read, understand, and follow the personal protective gear precautions
on the Material Safety Data Sheets (MSDS) that will come with each
bottle, as I wouldn't want you to grow a 2nd nose or something! If
they don't give you an MSDS with each bottle, then ask because they
are required by law to furnish them to you.
You will have to apply the primer to both surfaces & then the 401
adhesive. This material is sort of like a "contact cement" for
polyethylene. For underwater use, it is recommended to run a bead of
Dow Corning Silicone Aquarium Sealer around under the edge of the
patch to prevent water intrusion into the joint. Use one of the
pigmented flavors of silicone sealant, as the clear will have much
less UV degradation resistance. Make sure the polyethylene sheet
you use to make the patches is also UV stabilized or the patches
won't last very long in the sun.
I would still recommend the inner and outer patch method
mechanically held in place with pop rivets as detailed below.
This repair method will keep the adhesive/sealant joint in permanent
compression for reliable leak-proof performance. It will actually
make the hull stronger in the vicinity of the patches, and could be
repaired if a patch wears out.
This is my best shot at repairing your dinghy. If this method
fails, then I would junk it.
S/V Dynamic Equilibrium