Boat Welding Demonstrated

[RandyJ]

From the guys at LiquidLogic...great info.

http://www.youtube.com/watch?v=5bos4lfOA3k

[BEubanks]

Looks like a tool I might like to add to my boat repair box. Any recommendations on where to pick up one of those hot air welders and supplies for a reasonable price?

[travis]

We've got the plastic weld here at the shop. I picked my heat gun up from Hobby Lobby--it was branded as an embossing gun back in the crafting and appliques section for about $25.

-Travis

[BEubanks]

Good to know. Do you carry colors for the various boats you stock?

[travis]

Yep, we sure do.

-Travis

[Richard]

I summarize this http://forums.outdoorsdirectory.com/sho ... php?t=4253" onclick="window.open(this.href);return false;

bullseyetradingpost.com
last fall I heard about a web site bullseyetradingpost.com they offer a patch kit for polyethelene canoes, I got it followed the instructions, no heating with a torch, no hassle, no problem if I can do it anyone can.

two part bumper repair material (Bondo Easy Finish)
I drill several 1/8 inch holes about a half inch apart around the area I need to patch and then use a two part bumper repair material that you can get at the Auto parts store. I push the paste material thru the drilled holes, and put some paste on both the inside and the outside of the canoe. I make sure I have the ample mixed paste on both sides. You can smooth it pretty good with a putty knife or a popcicle stick.

Sikaflex 291
Just make sure the canoe area is scuffed (gouged) well--use a 24-36 grit on a grinder or polisher. Most plastics continue to ooze a mold release (on a molecular level) when sanded, but the sika-flex doesn't seem to mind, just wipe the repair area with a thinner and allow to dry before applying the product.

Loctite 401 in conjunction with the Loctite 770 Primer
In terms of adhesives suitable for HDPE (High Density Polyethylene) - Loctite 401 in conjunction with the Loctite 770 Primer is probably the most promising adhesive for bonding HDPE patches, not certain however of its water resistant/proof properties - Loctite suggested using the adhesive for the patch followed with a suitable RTV silicone around the edge to form a waterproof barrier.
See http://tds.loctite.com/tds5/docs/NEW-CA401-EN.PDF" onclick="window.open(this.href);return false; and http://tds.loctite.com/tds5/docs/770-EN.PDF" onclick="window.open(this.href);return false; for technical datasheet. The product specs for 701 appear to suggest that 701 is quite resilient to water even after 5000 hours of exposure.

Scotch Weld DP-8005
3M also make a product called Scotch Weld DP-8005 http://www.3m.com/intl/kr/img/adh/adhes ... DP8005.pdf" onclick="window.open(this.href);return false; which will bond HDPE, however it breaks down when exposed to water for prolonged periods, further, you need to purchase a special dispenser which is very expensive (many times more than the actual adhesive).

"Patch 'n Go"
Several days ago I came across a product that also sounds quite promising called "Patch 'n Go" http://www.moldingraphics.com/Foreign/1Italian/PNG.htm" onclick="window.open(this.href);return false; , essentially it's a form of semi solidified plastic compound which can be moulded and shaped to suite the crack/hole area and is then activated by use of a low burning flame causing it to weld to the surrounding plastic. Unfortunately I cannot locate a supplier/distributor here in Australia, however in your part of the world it appears to be readily available.
see: http://www.combust.com.au/plastic/polyol.htm" onclick="window.open(this.href);return false; & http://www.a-a-i.net/polyethylene.htm" onclick="window.open(this.href);return false; for detailed procedure and description. I am wondering whether the flame treating could be used in conjunction with the sanding suggested by Frank to further increase the bonding of the Sikaflex 291 to the plastic?

Some other useful links:
http://www.plentypupule.com/weldkit.htm" onclick="window.open(this.href);return false;
http://oakorchardcanoe.com/detail.php?product=2440" onclick="window.open(this.href);return false;
http://www.patchngo.com/" onclick="window.open(this.href);return false; (note: this is not the same as the "Patch 'n Go" mentioned above.
http://www.marinetex.com/PRODUCT%20PAGE ... ctions.htm" onclick="window.open(this.href);return false;
http://www.polyprocessing.com/pdf/te...yleneParts.pdf" onclick="window.open(this.href);return false;