• Announcements

    • Zapata

      Abbreviated rules   07/28/2017

      Underdawg did an excellent job of explaining the rules.  Here's the simplified version: Don't insinuate Pedo.  Warning and or timeout for a first offense.  PermaFlick for any subsequent offenses Don't out members.  See above for penalties.  Caveat:  if you have ever used your own real name or personal information here on the forums since, like, ever - it doesn't count and you are fair game. If you see spam posts, report it to the mods.  We do not hang out in every thread 24/7 If you see any of the above, report it to the mods by hitting the Report button in the offending post.   We do not take action for foul language, off-subject content, or abusive behavior unless it escalates to persistent stalking.  There may be times that we might warn someone or flick someone for something particularly egregious.  There is no standard, we will know it when we see it.  If you continually report things that do not fall into rules #1 or 2 above, you may very well get a timeout yourself for annoying the Mods with repeated whining.  Use your best judgement. Warnings, timeouts, suspensions and flicks are arbitrary and capricious.  Deal with it.  Welcome to anarchy.   If you are a newbie, there are unwritten rules to adhere to.  They will be explained to you soon enough.  
overdraft

How low can you go? Polyester

Recommended Posts

I'm adding a fitting with a backing plate. I want to mix up some polyester and microballoon goo as filler between the undersurface of the deck and the backing plate... 

only thing is... it's 40° (4°C)... can i put a wee heater inside to keep it a bit warmer? Will it set up anyway? Do I have to wait for spring?

Thanks!

Share this post


Link to post
Share on other sites

Yes, you can heat the space. I've done lots of polyester and epoxy work in the middle of Vancouver's winter (similar temps). The epoxy would take 5 days to get really hard.

I don't know how polyester works with cold frankly, so heating is the simple way to do it. Just don't burn the boat down. With polyester an hour will do it.

Share this post


Link to post
Share on other sites

This Sunday should give you a decent window of opportunity - supposed to get up to 11C.

Otherwise a heater is highly advisable if it can get you close to 10C.  Crank up the MEKP ratio to close to 3%.  

There are limits to how much you crank up the MEKP.  If it doesn't start to gel after about 40 minutes, scrap it.

It may still harden but greatly reduced mechanical properties IIRC

Without a heater and you are facing 4C, I wouldn't even bother trying it.

Edit - a heat gun or halogen lamp will also heat things up.  Something to kick start the reaction, which should generate some heat of it's own to help things along, if it is not too thin a layup .

Share this post


Link to post
Share on other sites

The most important variable in this discussion is the temperature of the resin. Warm up the resin before adding the hardener. Do not add extra hardener thinking its going to make it cure faster. It messes up the final product if you exceed 3%. It shouldn't matter if the substrate is cold. 

We do this all the time with epoxy resin. Its also a nice trick to make it runny in normal weather.

Share this post


Link to post
Share on other sites

^ +1. Warm the resin and backing plate. Small heater will suffice. I used 1000 watt ceramic car heater. If you can set the heater under the work the column of rising air will keep it just about right for an overnight cure

Share this post


Link to post
Share on other sites

I much prefer lamps to heaters. 

We like the 125 watt brooder lamps as they don’t ever heat enough to burn. 

My Shop has about a dozen of those clamp on lights with the  big silver “mixing bowl” reflector. I have found places like Tractor Supply in the US or Canadian Tire in Canada tend to have clamp and on lights with the nicest clamps. 

As the heating is radiant they will warm the surface in a small area even when there is a light breeze. 

Share this post


Link to post
Share on other sites
40 minutes ago, cameron said:

I've done similar work using System Three's Cold Cure epoxy.  No heaters or lamps.  All good.

Everything comes at a price.  Probably an ideal resin system for this particular application though.

However the tensile strength of Cold Cure is about 20% less than most other epoxy formulation.  Also, viscosity is listed as 1,660 cps, which is about double that of S3 Silvertip laminating resin and WEST 105/206.  Again, fine for the OPs purpose, but I wouldn't try laminating with Cold Cure.  

 

Share this post


Link to post
Share on other sites

I was replacing some rotten deck core from the interior of the boat.  Used it to bed the new core and stick the old skin back on.  Worked fine in this application.  Might not be the best for many other projects though.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now