I have a P51 with a cracked section.
Something tells me that acetone can be used to weld the acrylic back together. Am I right?
If not, what glue is good for it?

Regards

Richard.

The problem is that the hoods are not acrylic, they're lucite, which is very different. You can try Tenax 7R, but I haven't found the repair to be very solid. There are other solvents (which ones escape me at the moment) but the idea of having that particular toxic solvent around didn't appeal to me.

Check Paker51.com for replacement hoods. I think Ernesto usually has some listed on his site. The cost of a new hood and shipping is probably less than the cost of the solvent you would need to buy to do this correctly.

Cheers,
Sean

Replacement is the best option. The hood/shell does need to take some pressure when it is threaded on, so any repair will be likely to re-split. Ernesto www.parker51.com does have hoods for reasonable prices, and that's what I recommend as well.

The only exception to this would be a scarce color... mustard, buckskin tan, etc... where a replacement would be hard to find. But in that case I would send it to someone who had experience in doing this type of repair.

Oh, and you said "section" in your original post, I am assuming you mean the hood/shell. But if it is another part... Ernesto has those too, and replacement is also the recommended option. :-)

http://www.vintagepens.com/catill_nibs_parts.shtml

Has 'innards' for the "51".

Ron

Thanks for your help.

I will bear in mind the possibility of buying a replacement shell, but the crack is not yet severe.

I note the difference between Lucite & acrylic, so I'll not use acetone. Instead I'll try drilling the end of the crack to blunt it, then use some Permabond 737 (a toughened cyanoacrylate adhesive) that's black in colour to glue it. Fortunately the section is black, and I can borrow a tube of the adhesive from work and return it with only one drop used.. They use 50 odd tubes a week where I work for bonding rubberised components to a variety of metals and plastics, and the adhesion range of this adhesive is wide enough for it to be termed 'Black Magic' by those who use it. I know, from accelerated life trials, that it has a life of 25 years, so it shouldn't deteriorate if it proves to be adequate from the strength point of view.

Regards

Richard.

I looked into buying some "black magic" a number of years ago - the stuff was running at around $100/tube, and it wasn't a very big tube either!

What!!!!
I'm very glad I don't have to shell out for a tube. The shelf life is only 3 months or so too. The tube I've borrowed is only 20 grams..

Regards

Richard.

Shelf life can be extended on this by refridgeration. I have used that stuff industrially and it is very good. Thing is though, unless you have a black pen it will show up like crazy. That and it is really hard to get off of skin.

Cheers,
Sean

Methylene chloride works well as a solvent, it's sold by retailers specialized in plastics and some hobby shops.
That being said I have found that attempting this kind of repair is futile.

Interesting note on the Permabond 737.

First, I was wrong about the price - one site has it for a little under $27. Still, pretty expensive.

Then reading the data sheet, I came across this:

"Boiling water will destroy the bond in less than 24 hours, and this process is accelerated when the solution is alkaline." This is the hardened form of cyanoacrylate. Granted, we aren't boiling pens, but a warm moiste environment will still cause the bond to fail.

Ron,

You will never become a successful shyster or politician reading data sheets ...

Ron