Recent Topics
Unopened quart of MMO - Chicago
by Hollow
10/25/14 06:12 PM
Craftsman Tractor Doesn't Shut Off Immediately
by mez
10/25/14 05:45 PM
Found Ultra 0w20...go for it?
by BTLew81
10/25/14 05:43 PM
Anyone still have a VCR?
by chiefsfan1
10/25/14 05:14 PM
Time for OEM battery change?
by chiefsfan1
10/25/14 05:09 PM
Bought the wrong oil filter.
by joegreen
10/25/14 04:42 PM
Air Filtration - Lawn Mower Engines
by lawnguy
10/25/14 03:46 PM
Berryman Chem-dip and B-12 Chemtool.
by GreeCguy
10/25/14 03:33 PM
It's Not About The Nail
by JerryBob
10/25/14 01:27 PM
Windows Scripting Tool?
by sleddriver
10/25/14 01:10 PM
calcium sulfonate quiz
by miro
10/25/14 12:50 PM
BATTERY QUESTION
by lucerne06
10/25/14 12:42 PM
Newest Members
PhxAZ, Miramonte, Rotario, ignat, aahull
51695 Registered Users
Who's Online
93 registered (147_Grain, AandPDan, 19jacobob93, 13Tacoma, 69P, 77GrandPrix, 8 invisible), 1538 Guests and 206 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
51695 Members
64 Forums
221198 Topics
3497352 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG

Topic Options
#3331803 - 04/02/14 09:38 PM Solvent welding advice needed
sipman Offline


Registered: 05/27/12
Posts: 10
Loc: philly
Hi,
I have a 83 vw rabbit that some of my trim pieces have cracked. I experimented with Solvent welding using PVC Cleaner. This cleaner is Acetone and M.E.K. It worked great! I used metal Duct tape to hold the two pieces together. The nice side of the trim has a leather like texture molded into the plastic. The solvent went through the crack, and it appears it dissolved some of the adhesive and redeposited it onto the plastic.
SO needless to say, the crack is still visible. Do you think if I used a hot glue, or perhaps silicone caulk, I could seal the nice side so that the solvent doesn't find the adhesive? Will the Acetone and M.E.K. dissolve the hot glue or the silicone?

Top
#3331840 - 04/02/14 10:19 PM Re: Solvent welding advice needed [Re: sipman]
JimPghPA Offline


Registered: 08/22/09
Posts: 2818
Loc: Pittsburgh,PA U.S.A.
To weld plastic with a solvent use THF.

To glue plastic use Loctite E-20HP or E-20NS. The NS stands for no sag, meaning it will not run. You will require the dispensing gun. You can get the epoxy and dispensing gun from McMaster-Carr.

To heat weld plastic use a hot welding set made for plastic.
_________________________
Boy will I be happy when ALL vehicles on public roads are autonomous.


JimPghPa


Top
#3331846 - 04/02/14 10:23 PM Re: Solvent welding advice needed [Re: sipman]
robshelton Offline


Registered: 07/10/09
Posts: 448
Loc: Winston-Salem, NC
I've had good luck using pvc/cpvc pipe cleaner and solvent weld cement. But you need to be sure and not get any that has a color on the label. Not purple, etc. Sometimes you will need to bond a small piece of flat plastic behind the break to help support it if the material is thin. That is if there is room for it.
_________________________
1993 Camry 2.2 AT 415k - How far will it go?
1999 F150 4.2
2000 Camry 2.2 AT

Top
#3331852 - 04/02/14 10:28 PM Re: Solvent welding advice needed [Re: sipman]
sipman Offline


Registered: 05/27/12
Posts: 10
Loc: philly
What would brand name for THF be? I like using stuff I can walk out a store with, vs having to start an account with.

Top
#3331860 - 04/02/14 10:43 PM Re: Solvent welding advice needed [Re: sipman]
JimPghPA Offline


Registered: 08/22/09
Posts: 2818
Loc: Pittsburgh,PA U.S.A.
THF is sold in big drums. Any decent plastic molding company will have it. It is hard to keep in small bottles because it evaporates way to easy. It also has very low surface tension so it is easy to spill. I got some from a local plastic factory that does vacuum molding. I was there to discuss a project and we got to talking about glues, they gave me a little bottle of it for free, but they first gave me a print out of the MSD for it. I did a test by using it to weld two pieces of plastic together and then put the plastic in a clear oil. Those pieces have been sitting in that clear jar of oil for about a year now and they are still well joined.

Other than getting THF from some plastic factory I don't know where to send you to get some. I did not see the drum but they said they buy it by the drum. Probably 55 gallons.
_________________________
Boy will I be happy when ALL vehicles on public roads are autonomous.


JimPghPa


Top
#3331861 - 04/02/14 10:45 PM Re: Solvent welding advice needed [Re: sipman]
JimPghPA Offline


Registered: 08/22/09
Posts: 2818
Loc: Pittsburgh,PA U.S.A.
BTW even with the cap on correctly, the small amount of THF I had managed to evaporate.
_________________________
Boy will I be happy when ALL vehicles on public roads are autonomous.


JimPghPa


Top