• Untitled Document

    Join us on March 29rd, 7pm EST

    for the CBEC Virtual Meeting

    All EYO members and followers are welcome to join the fun and get to know the guest speaker!

    See the link below for login credentials and join us!

    March Meeting Info

    (dismiss this notice by hitting 'X', upper right)

Heatgun to strip epoxy too ?

Sven

Seglare
Can I use the heatgun to strip off some of our recently applied epoxy ? I assume so but am always ready to be educated before I make the mistake myself :)

I was apparently right in worrying about the hardener pump not pumping enough catalyst. It seems as if the epoxy did not cure completely, even after a few days, so now I want to get it off and re-do it. In the thick areas it is too soft to sand.


-Sven
 

treilley

Sustaining Partner
I have used a heat gun to remove epoxy. It works fairly well. Of course this was fully cured epoxy but that should not matter.
 

Emerald

Moderator
Hi Sven,

When I saw your first post on the epoxy hardener issue, I was thinking you were in trouble. You may have seen it, but West System has a nice overview of the cure process and properties of epoxy as it cures.

http://www.westsystem.com/ss/epoxy-chemistry/

In my experience, in "normal" conditions with an average pot size, let's say 8 oz., I'd expect the pot to kick within 30 minutes, and being well into the green stage around 3-4 hours out. The stuff should be getting pretty (rock) solid by 6-8 hours. Probably ready to wash down your amine blush and sand around 15 hours out. Obviously, I'm throwing out some general times, which all can vary some, but hopefully this will give you a feel on what to expect. Also, do wash that amine blush off before sanding, otherwise you'll grind it into the surface and potentially cause adhesion issues with whatever you put on next.

Just as an aside, epoxy is not compatible with fiberglass mat that is meant for polyester resin. The binding material that holds this type of mat together is soluable by the polyester resins, but not the epoxy. There is special mat for epoxy, that often is stitched to hold it together. Just thought I'd mention it so you can skip another "learning experience". :egrin:
 

Sven

Seglare
Thanks for those answers.

I didn't know about the amine issue. Lots to learn, preferably from others' mistakes :)

Thanks,



-Sven
 

Martin King

Sustaining Member
Blogs Author
Sven,

A heat gun will take it off. I've been there. I love west epoxy. It's
a wonderful adhesive to work with. I don't like it as an underlayment
for exterior brightwork, however. At first it seems great. You can
get a fast buildup of coating in a short period of time. But remember
that the wood is going to move, particularly if the piece is exposed
to heating/cooling cycles, and if there are any scarfs, or joinery that
might move, you are screwed. I've also seen it where the epoxy
turns cloudy underneath a proper buildup of varnish and had to
be stripped off as well.

For the first couple of coats on exterior brightwork, I am using
Smiths penetrating epoxy. This formulation is slow curing and
can be used as a tie coat underneath a varnish. A friend of mine
owns a large schooner with acres of exterior brightwork. This is
where I first saw Smiths used and the results I saw were impressive.
Don Dannenberg also touts it in his book on wooden runabout restoration.
I suggest you check it out before committing to a recoating schedule.

I have no affiliation with the product, blah blah blah... just a satisfied
customer.

Martin
 

Emerald

Moderator
Hi Martin,

I'm battling what appears to be a water saturated toe rail. As I've varnished it, I have spots where the film was intact, but water appeared under the varnish in cold weather after 7-9 months - you could literally push the water bubbles around - cool for the first 2 seconds, until reality sinks in :esad:

I took it back to bare wood last spring, and started working with oil on the hope it would breath some and I could get oil in to displace the water. It has held up reasonably well, and I was getting ready to do some more, but now I'm wondering if I should try a section with Smith's CPES. Have you tackled a piece of moisture laden wood with the Smith's, and how long did it take to have it all work? If I understand CPES, it has some ability to remove moisture as it cures. Really wondering if my scenario is pushing the limits of the product. Any first hand experience on this?

Thanks
 

Martin King

Sustaining Member
Blogs Author
Hey David,

That sucks about your toerail. You raise an interesting question and
I don't have an answer for you. I was more interested in getting dry wood
sealed and tieing in to the varnish coats. From what I understand, it
will soak in to wet wood and displace the water to a degree. I'm just not
sure to what degree. You should contact Smiths directly.

Martin
 

Glyn Judson

Moderator
Moderator
Water in the teak.

All, This is slightly off topic because it doesn't deal with epoxy issues, just water in the wood issues. My friend Gary in Gig Harbor WA has never been able to keep varnish on the cap rails or eyebrow molding of his E31 hull #19. In time, measured in weeks, sometimes months, the varnish he applies, begins to bubble and eventually blister the varnish leaving raw wood from moisture beneath. In all the years he's had the boat he's never been able to solve this problem and keep varnish on the teak for any length of time. I'm sure it's moisture in the wood as you're experiencing David. We have the same teak in the same places and mine never has done that. Glyn Judson, E31 hull #55, Marina del Rey, CA
 

Martin King

Sustaining Member
Blogs Author
Yeah, wet wood toerails are a problem. My dad had this problem with his
old 36. The moisture eventually lifts the varnish film off from underneath.
Very frustrating problem, for sure. The water gets underneath what's
left of the old bedding compound (usually dolphinite) and gets trapped
there. Short of drying out in a heated building for a year, I can only
think of one thing that will work for sure, and that is replacing the
toe rail. Having done partial replacement on my own boat, I can tell
you that it's not a fun project nor inexpensive, with the current cost
of teak now headed for the stratosphere. David (and Gary) you have
my sympathy.

Martin
 

Lucky Dog

Member III
sealing the water out

When i was in high school I restored a 19 foot Arrow sailboat that was 1 inch solid mahogany planked hull and several old town canoes. The arrow was moored all summer. In college I restored stinky chris crafts to pay for grad-school. My guess is your toe rail is not completely sealed. Water is weeping in from the underside and is trapped in the wood until it can blister the varnish. Every piece of wood i have taken off our e35-II was not sealed from the under side. Teak is a oily wood, it could be the new oil that you put on before varnishing. Just a thought....

ml
 

Emerald

Moderator
I had decided as I was staring at this last spring that I was probably sucking moisture up from under the toerail. Martin's dad's experience on his 36 meshes with this as well. I had been thinking that in lieu of removing the toe rail, which I really want to avoid, I might try running a bead of caulk down the deck side of the toe rail to keep deck runoff from going directly under it, but then leaving the outboard side "as-is" so it would hopefully drain/aid any moisture locked in getting out. Does this make sense to you all as an approach?

Didn't mean to hijack your thread Sven, but hopefully this all ties together in the big picture :egrin:
 

Martin King

Sustaining Member
Blogs Author
David,

You could try it but I think realistically if the wood is wet underneath,
well, the solution is to lift it up off the glass enough to allow air
to circulate and then to dry completely. Easier said than done. The reality is that drilling out 100 or so bungs perfectly, and then backing out the
machine screws without stripping the heads is nearly impossible. Unfortunately
to do it right, you are looking at replacing the wood. In my dad's case,
he opted to just sell the boat! Anyway, that's my take on it. Maybe
some one else has a better solution.

Martin
 
Last edited:

Sven

Seglare
Didn't mean to hijack your thread Sven, but hopefully this all ties together in the big picture

It's all very relevant as far as I'm concerned. The West System admonition to undercut installed wood a 1/4" and fill it with epoxy if you couldn't coat all sides certainly rings true.

After this weekend we bring the heatgun back home and strip the hatch frames, then we try Smith's Penetrating Epoxy if we can find some.

So much work and so little done yet :)


-Sven
 

Emerald

Moderator
Finally got a few moments to call Smith's about using the CPES on my water laden toe rails. The feedback I received is that it should work to displace water and seal the wood and I should be able to keep varnish on when done. The general approach will be to do this when the wood is as dry as possible already - so wait until after our spring rain is done - and to brush the CPES on until the wood is saturated. It should reach a point where the wood won't absorb more and there will be a sheen. At this point let it cure and varnish. So, I'll do a test section and we'll see what happens.
 
Top