Hot glue test

[firestang]

Thats what we found as well.
We got the measurements all wrong on one pontoon and decided to see how well it held together as we had glued every join and smoothed it like you would a resin fillet before it dried. It took two of us to rip it apart.

[goanywhere]

That is what we did with the one in the foreground, well we actually stitched it properly and had the gaps set right and then tacked it with glue first. It was solid as a rock and we were almost tempted to run glue all around all the seams. It is solid with the proper fillet material over the glue so that one worked very well.

So you stitched and set the gaps first, then hot glued to tack the seams. When tacking with the hot glue, did you take care to keep the glue inside the seam and not protrude outside? This could be done by hot-gluing from the inside rather than the outside, and being careful to only use small beads. Sanding hot glue is almost impossible, it just melts and goes everywhere.

Did you pull the stitches before filleting? I would think that would save time if you did, because pulling stitches after tacking with epoxy, then going back and filling the stitched areas would be time consuming.

The other thing, at the stage where checking the levels on the saw horses, if the seams have been hot-glue tacked only it would be much easier to adjust things to level them up than after they have been epoxy welded. Hot glue can be knocked off and reapplied very easily, whereas epoxy is pretty much permanent once cured. If you found that your boat had a serious twist in the hull, you could almost disassemble it if necessary to adjust it if it has been tacked with hot glue. I don't think that would be possible with epoxy.
I found a site where a guy details how he tacks the timber strips in placed as temporary welds in strip-built boats. http://www.laughingloon.com/shoptips2.html

[firestang]

We did tack it from the inside, and got some glue all the way through , but we also used it as the fillet on the inside as well, not to make something in a new and amazing way but to see what would happen "if" .

It was more a trial on what could be done with the stuff .
More like , "oh look a glue gun" , lets try that" We didnt use a timber compatable type either as the ply was scrap packing material.

We sliced the bits the protruded and found that when we glassed it that it did'nt disolve if the resin was made to go off in normal time. Same goes with the standard fillet material you would use.

So for a small internal tack before filletting the inner and outer panels id use it. For internal bulkheads where it would not be seen id definately use it.

We did do someexternal sealing with it and you can see it under the glass but if we smoothed it correctly there was no ridge to be noticed , but id be painting the final product though , and the glass did stick to it.

I just looked the site you talked about , thanks for the link.

[goanywhere]

Well, now I am into my Sabalo build, and I have some more interesting feedback on the use of hot glue.

I decided to use the hot glue to 'tack' the pieces of the cockpit and tankwell sub-floor frames to hold them as I glued the timber quads on. I was having all sorts of problems keeping the shape and stopping it from wobbling about, so I just applied a small bead to one corner of each intersection, then I epoxy glued the quads in place on 3 sides, waited for it to cure off, then just knocked off the hot glue bead with a chisel and glued the fourth one into place. It worked like a dream. This is definitely one application I would recommend for hot glue in S&G building.