Sandable adhesive for semi-fill purposes?

[Thorne]

This is a repost of the thread that somehow transmuted into homemade anchors.

I've been using Vulkem 116 for places where a permanent bond of flexible material is needed -- like between fir bottomplanks and between strakes.

But when using PL Premium to fill even small gaps where I want a hard, sandable fill -- it bubbles up and creates an uneven surface. The bubbling is the worst part of the PL Premium, as otherwise it seems to bridge the gap fairly well.

So what tube-type product can I use? I searched all the threads on the topic, and it seems that any of the polyurethane sealants (5200, Vulkem 116, PL Premium, PL Premium Concrete Sealer) are best used for places where a non-sandable permanently flexible compound is needed.

Would a polysulfide product work better? I read some mentions of using 4200 instead of 5200.

Again, I'm looking for something that will harden up fairly well and be sandable -- and would prefer not to bother with epoxy or epoxy fairing compounds as the mess and expense seems excessive for the purpose.

Thanks! Getting close to splash-down on the boat, largely due to the invaluable assistance from this forum.

[ 02-25-2006, 10:54 AM: Message edited by: Thorne ]

[capt jake]

What? No more anchor??? LOL smile.gif

Nothing to offer as to your question other than I have tried polyurethane adhesives to 'brige' the gap (or a small fillet) and it bubbles unsightly every time.

[videoguy]

I wonder if plain ole bondo would work?. smile.gif ..Phil

[Ron Carter]

Yup. For cosmetic repairs bondo works well. I have used it in extreme cold and being polyester resin based all you have to do is kick up the hardener to get it to go. If you work it down with a cheese grater before it completely cures it is easy to shape and remove over fill. Don't wait till it completely cures or it will be much harder. Above thanks to an old body man neighbor.

[sdowney717]

Wait for the pl premium Construction adhesive to set up till its half way finished hardening and then work it back down with a putty knife or your finger. I view the swelling as a plus for filling seams. Take a putty knife and use a back and forth motion to force it down.

You can also mix it with saw dust and it will bubble up even more, when you press it back down it sets up into a very nice filler.
with all the moisture cured polyurethanes you can speed up on the cure if you mix in some sawdust.

Whats nice about the PL, is you can sand it down easily and get a decent looking surface.

I have had to go back and fill bubble holes with more material after sanding.