122Views7Replies

Author Options:

Will hot ethanol eat through flame hardened PVA glue? Answered

I'm still working on this solar thing and it's coming along pretty well, am starting in on the final piecing of things together.

One old problem that has resurfaced tho is the sealing of the boiler. I was using a metal epoxy similar to Quicksteel, which handled the ethanol ok but is going soft and cracking off, I think due to the regular heating > 80C.

So I'm once again looking around for other options. What I'm trying now is wood glue, which I assume is just PVA, run over a flame so that it becomes hard. It seals the ends of the flattened copper pipe well, and doesn't immediately fail on contact with ethanol.

Is it likely to hold up, do you think? I'm kind of assuming it won't, but it'd be great if it did.

cheers

Daniel.

7 Replies

user
lemonie (author)2010-01-11

I do not think PVA will work better than epoxy. Have you used an epoxy which specifically states that it can be used for fuel-tanks, because that's what I'd try next?

L

Select as Best AnswerUndo Best Answer

user
SolarFlower_org (author)lemonie2010-01-12

I think the metal putty I've been using is a kind of epoxy. I'll have a look for something that handles higher temperatures.

ta.

Select as Best AnswerUndo Best Answer

user
lemonie (author)SolarFlower_org2010-01-12

It'll be similar to this:
Plastic_Padding_Chemical_Metal
But that claims solvent resistance (not hot though...)

L

Select as Best AnswerUndo Best Answer

user
SolarFlower_org (author)lemonie2010-01-13

Soldering would definitely be the best way. But I'm trying to keep this thing as low tech as poss, so no demanding skills or tools.

I ended up getting this stuff:

http://www.pattex.es/v2_gama.asp?f=5&sf=11

(34, the one on the end)
which claims a max temp of 150 C and resistance to 'disolventes usuales', but whether that includes ethanol I don't know. You'd think so, tho.

So far I've tried quicksteel (which seemed to work real good, but can't seem to find it outside of Australia) that chemical metal stuff, (which really didn't handle the heat at all), some Danish stuff which is basically identical to quicksteel but doesn't function, and now this Spanish nural 34 stuff.

I'm some kind of International Man of Metal-epoxy.

Select as Best AnswerUndo Best Answer

user
lemonie (author)SolarFlower_org2010-01-13

If you get the thing to work as you would like, you can fiddle with the materials later. Get your machine together, then look at the simplifications. That epoxy looks worth a shot.

L

Select as Best AnswerUndo Best Answer

user
SolarFlower_org (author)lemonie2010-01-13

I know...
However, my work space is currently the floor of a dark back room in a squat in Málaga. My most complex tool is a rivet gun. So unfortunately soldering or anything like it isn't really an option either way.

tho I could've had it done on the barge in Copenhagen, man that workshop was sweet...

*sigh*

Select as Best AnswerUndo Best Answer

user
NachoMahma (author)2010-01-12

.  Would soldering or brazing be an option?

Select as Best AnswerUndo Best Answer