Have I gotten the second best solvent for doing a solvent weld?

[Ink Stained Wretch]

I've finally gotten around to trying to repair some cracked sections that I have on fountain pens that I'd like to be able to use again.

 

I was told that what I need to do is a solvent weld of the plastic. My problem is that I might have bought the wrong stuff.

 

One pen is a Waterman Phileas with a broad nib that I liked. The section suddenly developed a hairline crack in it some years ago when I was using it in my rotation. The section is black plastic. I don't know which kind of plastic it is.

 

The other is a "Harley Davidson" fountain pen that I think is a Waterman Kultur fountain pen with the motorcycle company branding. It also has a black, plastic section. I'm not sure that it's the same plastic as the Phileas section is made of. On this one I know why the section is cracked. I'd had the idea to really, really clean it before putting another ink in it years ago, and so I decided that I'd pull the nib and feed. I'd figured out that I could pull a nib and feed out of a fountain pen maybe a year or so before that, and I figured I could always just do it. Well, this pen's nib and feed were pretty tightly held by the section. So when I went to use that "Harley Davidson" fountain pen I found it leaking all over my hand and I traced the leak to the crack in the section. This crack is, I think, a little bit wider than a hairline.

 

So it was suggested here on FPN that I get some solvent and weld the section cracks shut. MEK aka methyl ethyl ketone aka Butanone was suggested as the solvent.

 

A hobby Web site was suggested as the place to get it. I finally got the solvent from that hobby Web site, but it turns out to be methylene chloride aka DCM aka Dichloromethane.

 

So did I really get the wrong stuff, or is the methylene chloride probably going to work?

 

Another question relates to applying the solvent. The bottle has this relatively huge brush in the cap. I see that applicators for this stuff are sold at that hobby Web site but I'm wondering if the eye-end of a sewing needle might be good enough as an applicator? Any advice on this?

 

Thanks for any help.

[FarmBoy]

The solvent you use depends on the polymer you are trying to solvent weld. 
 

I generally don’t attempt welds on modern injection molded plastics, such materials often have to much garbage I n the mix to make clean bendable welds. 

[Doug1426]

3 minutes ago, FarmBoy said:

The solvent you use depends on the polymer you are trying to solvent weld. 

 

FarmBoy gave you solid (no pun intended) advice.  In that regard, here is a link to a good site for correlating plastics and the solvents that will work:

 

http://www.spiuserforum.com/index.php?threads/solvents-used-for-welding-plastics.2652/

[Ink Stained Wretch]

4 hours ago, FarmBoy said:

The solvent you use depends on the polymer you are trying to solvent weld.

 

I'm going largely by some advice I got on this Repair Q&A forum some years ago. I suspect that someone may know what plastic was used by Waterman for their sections on the Kultur and the Phileas. Anybody here able to name that plastic? (Sounds like the start of a new game show 😊.)

 

Quote

I generally don’t attempt welds on modern injection molded plastics, such materials often have to much garbage I n the mix to make clean bendable welds. 

 

Well, my other choice is to consider the pens with the hairline or very thin cracks in their sections to be useless junk to be discarded because they can never be used in their current condition. I really liked the broad nib on the Phileas and I think that it would be pretty much impossible to remove the nib and feed from a Phileas section and get it installed in another Phileas section without cracking the section to which it's being transplanted, given my experience with the Kultur.

 

So from what I've been told, and from the situation I've observed with these pens I think that solvent welding is the thing that I need to try. I just want to make sure that I'm using the right solvent for these plastic sections. I'm hoping that someone here can tell me just what plastic is used for those Waterman sections.

 

I'm also hoping that someone may weigh in on using the eye-end of a sewing needle as the applicator for the methylene chloride.

[Ink Stained Wretch]

4 hours ago, Doug1426 said:

 

FarmBoy gave you solid (no pun intended) advice.  In that regard, here is a link to a good site for correlating plastics and the solvents that will work:

 

http://www.spiuserforum.com/index.php?threads/solvents-used-for-welding-plastics.2652/

 

Thanks for that link. I'm saving the text from that Web site for future reference.

 

[mizgeorge]

If it's made from ABS (or a number of other plastics), the solvent you have probably won't work, but acetone probably will if you can get hold of that, but can't source MEK.

 

As for using a needle as an transfer mechanism, yes, that would work - I'd recommend sticking it into the end of something a little longer to make it more manageable and to ensure you don't hurt yourself. I just use a very fine, natural hair, paintbrush.

[eckiethump]

I don't often do solvent welding anymore on celluloid, it shrinks the material. I use "Liquid Weld", which can only be purchased online and the solvent for it, bought separately, will melt celluloid. Suggesting it is a solvent weld, rather than just an adhesive or superglue type solution, which is hygroscopic.

eckiethump

[OMASsimo]

• You either need to know the material to find the right solvent or you can try. DCM works for many but not all plastics. 
• I think you need to remove nib and feed before welding.  Apply dry heat if it’s stuck too hard. The crack might have developed because the feed was jammed into the section too hard.
• If the crack has a gap, you can make a paste of some appropriate plastics and the solvent. I keep a box of broken scrap pens from which I can sand down material for this.
• The eye side of a needle should work ok. I prefer to use a glass lab syringe.

Good luck!

[Ink Stained Wretch]

15 hours ago, eckiethump said:

I don't often do solvent welding anymore on celluloid, it shrinks the material.

 

I'm not trying to solvent weld celluloid. That'd be another thread, which I'm glad I don't have to post.

 

[Ink Stained Wretch]

7 hours ago, OMASsimo said:

• You either need to know the material to find the right solvent or you can try. DCM works for many but not all plastics.

 

That's part of why I'm asking if anyone knows just what plastic Waterman used for the Phileas and the Kultur. I'm trying to find out if I have the right solvent in methylene chloride. I don't have any other Waterman sections to try on.

 

Quote

I think you need to remove nib and feed before welding.  Apply dry heat if it’s stuck too hard. The crack might have developed because the feed was jammed into the section too hard.

 

The crack in the Kultur occurred because I was clumsy in removing the nib and feed. The nib and feed in both the Kultur and Phileas seem to be really in tightly. The nib and feed of the Kultur were already out of the section, but given the tightness I do not think that I could get them back into the section without cracking it again, if I were to try putting it back in after I solvent welded the section. Given the tightness of the Kultur I don't want to risk pulling the Phileas nib and feed. I'm hoping that the solvent wouldn't do anything to the nib, which is what the hairline crack is right over.

 

[Ink Stained Wretch]

Well, I found some MEK aka methyl ethyl ketone on-line. It's a 200 mL bottle and it costs about $30 plus shipping. Wow, that is so pricey. And it really does look like it's not healthy stuff to have around.

 

In the silver lining mode of looking at things a Jinhao 992 partially fell apart last week. I picked it up by the clip and the clip and the top of the cap came right off. I'd heard about the Jinhao 992 plastic disintegrating. So the silver lining part is that as soon as I can get some time to do it I plan to try using the methylene chloride to see if the cap can be solvent welded back together again. If the methylene chloride can't fix it or if the repair messes up the pen it won't be much of a loss, given that some folks here on FPN have predicted that all of the Jinhao 992s are going to totally disintegrate in the near term.

 

Of course if someone can tell me just what plastic the Waterman Phileas and Kultur sections are made of that would help too 🙂 🤞.

[mizgeorge]

57 minutes ago, Ink Stained Wretch said:

Of course if someone can tell me just what plastic the Waterman Phileas and Kultur sections are made of that would help too

I don't have either (I don't have any modern Watermans), but I would hazard a guess at ABS.