Jump to content

Reducing waste with epoxy / glass / FRP / vac bagging etc


Recommended Posts

As I've been working through a rebuild project at home I've been somewhat astounded as to the amount of waste I'm making that's going to landfill. In my day to day life i'm no greenie nazi,. but do take a little care to separate the recycling, reduce single use plastic, only landfill what's really required, etc etc. 

The irony of sticking one of the strongest fibres known to man together with completely inert cured plastic just so I can play on the ocean isn't lost on me... Perhaps i should work with wood instead...

Does anyone have any hints for reducing the amount of disposable waste we generate? Some things I'm trying to do:

  •  Vacuum bagging, make the bag oversize, cut off the end and re-use it for the next panel
  • Tying to find reusable mixing pots that don't crack trying to get the old stuff out. 
  • Buying better spreaders/ mixing sticks / etc that can be cleaned and reused.

Peel ply- just have to accept this as waste I guess. Likewise breather fabric. 

Does anyone else have any ideas? Or care? Maybe I shouldn't ....

 

 

Link to post
Share on other sites

I mix and do some spreading with wood tongue depressors, $5/1000. If you wipe them off with your glove before you take them off they are good to go again once cured. Clean end of tongue depressor gets used to flip the first glove off so I don't get resin on  my wrist. 

Body shop bondo spreaders seem to last quite a while before the edges get too rough to use.

  • Like 1
Link to post
Share on other sites

I wipe squeegees after use.  The edge can be refreshed with a sharp plane.
Chip brushes get thrown into a lidded pot of acetone & are re-used.
1 qt. Poly cups from restaurant supply are cheap ($.18) and often come clean.
Wood stir sticks from paint shop can be wiped clean or cleaned with belt sander.
4 mil poly film is cheap vac bag.  Can be sometimes re-used.  There’s no saving peelply or breather.

Tongue depressors are dirt cheap.  Can be sharpened as scrapers with belt sander.
4 mil ziplock bags ($.08 in quantity) are good for applying fillets.

Just be glad that you’re not infusing,.

Link to post
Share on other sites

I used to measure my progress by the amount of stuff I had to throw out.

It is amazing how much extra stuff is used when you vac bag everything.

Even so I did a few things to help:-

1.-  I made a vacuum table so it only used one lot of vacuum film for all the flat panels.

2.- All other jobs were done with slightly over sized film so it could be trimmed and re-used also from larger to smaller jobs so film could be re-used over and over.

3.- For mixing containers I used 2 litre plastic ice cream containers because once the resin was cure it was easy enough to crack out and they become available once the ice cream is        eaten anyway.  So no big deal to replace them as they were to be thrown out anyway.

4.- .I  used 1 inch plastic scrapers for mixing . You can either clean them off with vinegar or crack the resin off once cured.

A mate told me about using vinegar to clean up and I ignored him for a long time. Once I tried it I was really surprised. Also good if you get resin on your skin as vinegar will clean if off.

5.-  As far as brushes,  I had a glass jar with acetone in it and a good lid. When I used a brush and was finished  it would go into the acetone until needed again. Just needed   to change the acetone now and then.

 

 

 

SAM_0089.JPG

SAM_0087.JPG

Link to post
Share on other sites
4 hours ago, Zonker said:

You can buy re-usable vac bagging film. It's not cheap though.

and not recommended for important jobs.  Has a habit of leeching silicon, teflon or similar (depending on brand) into laminate resulting in compromised resin/fibre matrices.

Link to post
Share on other sites
4 hours ago, The Mad Hatter said:

A mate told me about using vinegar to clean up and I ignored him for a long time. Once I tried it I was really surprised. Also good if you get resin on your skin as vinegar will clean if off.

Vinegar actually does a better job than acetone at cleaning up epoxy.  Vinegar kills the epoxy while acetone only thins it.  I've noticed when I have used acetone to clean epoxy from my skin there is always a slightly sticky feeling afterward whereas with vinegar it feels completely clean.

However, I would not store used chip brushes in a jar full of vinegar because unless you can clean off all the vinegar before using, it will kill any layup you do - and a  surprisingly little amount of vinegar will kill a lot of epoxy.  

  • Like 1
Link to post
Share on other sites
4 minutes ago, 12 metre said:

Vinegar actually does a better job than acetone at cleaning up epoxy.  Vinegar kills the epoxy while acetone only thins it.  I've noticed when I have used acetone to clean epoxy from my skin there is always a slightly sticky feeling afterward whereas with vinegar it feels completely clean.

However, I would not store used chip brushes in a jar full of vinegar because unless you can clean off all the vinegar before using, it will kill any layup you do - and a  surprisingly little amount of vinegar will kill a lot of epoxy.  

I think if you try to remove resin from your skin with acetone your skin is   likely to  absorb more of the thinned resin. Not a good option.  

It was also suggested that I clean my brushes with vinegar but I would never do that. Wiping  a scraper off was one thing but  I could never be sure that I could get all the vinegar out of the brush before using it again. It is surprisingly good at neutralising epoxy. It would be good to get a chemists take on why. All I know is that vinegar is acidic and I think epoxy is alkaline.

Any chemists out there that could enlighten me further?

Link to post
Share on other sites
8 hours ago, The Mad Hatter said:

I think if you try to remove resin from your skin with acetone your skin is   likely to  absorb more of the thinned resin. Not a good option.  

It was also suggested that I clean my brushes with vinegar but I would never do that. Wiping  a scraper off was one thing but  I could never be sure that I could get all the vinegar out of the brush before using it again. It is surprisingly good at neutralising epoxy. It would be good to get a chemists take on why. All I know is that vinegar is acidic and I think epoxy is alkaline.

Any chemists out there that could enlighten me further?

Yes -- according to my organic chemist father, epoxy is a glycidal base resin (usually phenols) crosslinked thru pH-modifying hardeners, in most cases an alkyl amine (pH ~11, moderate base). Doesn't take much acid to neutralize that base in a typical 5:1 stoichiometry (5:1 undiluted -- many epoxies dilute the hardener) and prevent crosslinking.

Interestingly, tho, acids can be used in lieu of bases to cure many resins, including exotic epoxies. Some aren't too fussy which direction you shift the pH, as long as it is shifted. From Wiki:

Quote

Curing may be achieved by reacting an epoxy with itself (homopolymerisation) or by forming a copolymer with polyfunctional curatives or hardeners. In principle, any molecule containing a reactive hydrogen may react with the epoxide groups of the epoxy resin. Common classes of hardeners for epoxy resins include amines, acids, acid anhydrides, phenols, alcohols and thiols. Relative reactivity (lowest first) is approximately in the order: phenol < anhydride < aromatic amine < cycloaliphatic amine < aliphatic amine < thiol.

 

  • Like 2
Link to post
Share on other sites
On 8/5/2019 at 12:36 PM, Diamond Jim said:

Just be glad that you’re not infusing,.

Not so.   Use scored foam or light cfm to spread the resin and all you need is peel ply, vac bag and tacky tape, the same as vac bagging, but without the bleeder full of resin that you end up with in a vac bag job.      On a flat table, brown tape the bag edges and you don't need the tacky tape.  

Use multiple inlets and leap frog the resin feed and there is less than a cup of waste resin.   In terms of plastic generated, infusion uses about half the weight of resin that hand laminating does, so you have a kg or so of bag to throw away, but save 10's of kgs of resin.  A no brainer in terms of environment, cost and weight.  

  • Downvote 1
Link to post
Share on other sites
  • 1 month later...

If you are vacuum bagging a panel on a table you can often reuse the peel ply and breather on other flat panel projects. If you don't over wet out the laminate the breather/bleeder does not get saturated..

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...