Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Other Technical Questions... => Topic started by: justboatonic on February 14, 2010, 09:16:14 pm

Title: Plastic Padding hasnt 'gone off.'
Post by: justboatonic on February 14, 2010, 09:16:14 pm
Grrrrr. Sanded the bulwarks down on the Envoy and applied a thin layer of Plastic Padding to give that smooth finish after further sanding. The first lot of PP has gone off OK but, the second batch I put on doesnt seem to have gone off as expected. May be its because I put the Envoy in the conservatory soon afterwards cos swmbo complained about the smell!

Must admit, it was a lot colder in there so maybe that's affected it?

Its only a thin layer so I should be able to scrape it off if necessary. Would applying heat do the trick or is it a basket case?
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: knoby on February 14, 2010, 10:59:03 pm
Although the lower temp will slow the curing time, if it hasn't set within 24 hours it's not going to. warming it up will help but thin layers seem to be much more sensitive to the amount of hardener you use. Unless it is exceptionally cold in your conservatory i would still expect it to set within 24 hours.
If you have any doubt I would remove it & try again, as the partially hardened filler will inhibit you getting a good finish.

Cheers Glenn
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Colin Bishop on February 14, 2010, 11:33:12 pm
I got caught like that on my old 1:1 scale boat. Did a bit of filling at just above freezing and the filler would not set. Try bringing it back indoors first. You might be lucky.

Colin
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: snowwolflair on February 15, 2010, 12:23:18 am
ITs a cascade chemical reaction.  It has to be warm, then smear a little of the activator on the surface and mix it a little. when this reacts it might cause the rest of the activator in the mix to go off as well.  Extreme cold kills of the chemical reaction which by necesity causes heat to create the chemical bonds.
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: justboatonic on February 15, 2010, 01:51:54 pm
Thanks for all the comments.

I had the hull propped up by a radiator. Have to say although the PP is harder than it was, its not rock hard ie you can just see a nail impression if you use your finger to press hard into it.

In these circumstances, is it better to scrape it off of put some more PP on top of it? Its only a very thin layer btw.
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Shipmate60 on February 15, 2010, 01:59:52 pm
In my opinion yes, get rid of it and start again.

Bob
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: justboatonic on February 15, 2010, 10:16:09 pm
In my opinion yes, get rid of it and start again.

Bob

Aye, that's what I ended up doing.  {:-{
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Colin Bishop on February 15, 2010, 10:20:49 pm
Now, if you'd been a time traveller you could have gone back and not put it on in the first place....

Colin
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Flying Sparks on February 16, 2010, 08:10:01 am
If swmbo compains about the smell why not put your model in the airing cupboard  :} Nice and warm and keeps the smell out of the house  :-)) Seriously though I agree with the others although it's a chemical reaction it still needs heat to cure. Epoxy resins are the same, no heat no cure.

Phil.
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Popeye on February 16, 2010, 10:46:51 am
If swmbo compains about the smell why not put your model in the airing cupboard  :} Nice and warm and keeps the smell out of the house  :-)) Seriously though I agree with the others although it's a chemical reaction it still needs heat to cure. Epoxy resins are the same, no heat no cure.

Phil.

I have an alternative solution to the SWMBO factor >>:-(.

Ditch SWMBO, :-) ,appropriate the airing cupboard for extra storage/ad hoc spray booth and use the PP anywhere in the boatyard (oops - house) that's warmish  :-)).

An additional benefit of liberating the fragrance of PP to the atmosphere will be that hoovering ,dusting, cleaning  etc. can be abandoned for perpetuity coz the premises will pong so much that there'll be no visitors to witness what a mess one lives in :}


A word of caution however; SWMBO's tend to be very tenacious  in their obsession with real estate and it takes a lot to shift 'em, so it may be necessary to add Ammonia to the list of smellies one uses in the pursuit  of one's real passion. :embarrassed:
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Nordsee on August 18, 2010, 09:09:08 pm
If swmbo compains about the smell why not put your model in the airing cupboard  :} Nice and warm and keeps the smell out of the house  :-)) Seriously though I agree with the others although it's a chemical reaction it still needs heat to cure. Epoxy resins are the same, no heat no cure.

Phil.
May I ask what a "swmbo" is? sorry, living abroad we miss all the "in" names and terms.
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Klunk on August 18, 2010, 09:32:01 pm
she who must be obeyed......rumpole of the bailey
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: RaaArtyGunner on August 18, 2010, 10:50:56 pm

Next question, who is She, a ship/  %) %)
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: dodgy geezer on August 18, 2010, 11:27:30 pm
she who must be obeyed......rumpole of the bailey

Umm... Rumpole was just quoting. The original SWMBO is Rider Haggard's.  http://en.wikipedia.org/wiki/She:_A_History_of_Adventure refers....
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: Klunk on August 19, 2010, 07:24:10 pm
I knew some one would go and look it all up!!! lol %%
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: DickyD on August 19, 2010, 07:27:10 pm
I knew who it would be.  {-) %%
Title: Re: Plastic Padding hasnt 'gone off.'
Post by: dodgy geezer on August 19, 2010, 09:01:31 pm
I knew some one would go and look it all up!!! lol %%

I'm wondering why you think I needed to look it up......  :o :o