Frame Selection

[Justan]

The reason I mentioned Michelangelo Moulding is that they sell in both the US and CA and offer a high quality polystyrene; but mostly because they sell through distributors. Due to that the OP may be able to get some quality polystyrene frames. Even tho they will probably cost more than $30 each they have a reasonable chance of helping to sell the art.

Never worked with a manual chopper. They seem a pain to use even if quiet other than the groans of the operator. Regarding the underpinner, while I’m not doubting your word, what air PSI do you run in the underpinner?

BTW I’m embarrassed to acknowledge it but after my last post I went back and read a bit about v-nails. That’s not the part that’s humiliating, but when reading it I found I incorrectly noted the application of v-nail types to wood media in my previous comment. According to this source: http://www.pfmproduction.com/pdfs/pfmp_spring06/pfmp_spring06_nails.pdf

Underpinner nails come in different grinds—that is, different angles on their cutting edges designed for either soft or hard wood. They are normally ground primarily on one side, with a small grind on the other to remove burrs. MDF nails are ground equally on both sides so the point is in the center of the nail. A softwood nail also has a sharper angle than a hardwood nail. “A softwood nail is sharper and cuts through the fibers like a knife to create a stronger assembly in softer woods,” says Convey of ITW AMP. “Hardwood nails are blunter and crush through the fibers of the wood. The bigger the nail, the more material you press into, the more important it is to have the proper grind. MDF also takes a thicker nail. While our hardwood nail will work in a lot of MDF, what’s called MDF is often high density fiberboard. That takes a thicker nail because a normal hardwood nail will bend in the material.”

The rest of the article is a good read. The reason I mention this is both to correct my post and also suggest that enough air pressure and perhaps a different type of nail (MDF) would have done the job…

Received a 90 lb box of 2.25” wide moulding yesterday and need to put G2 goo on some stuff and make frames for the show next week. That will be the first major Art show of spring and the last indoor show until next October. Almost time to put away the lights and carpet and get out the 10' x 20' canopy and add 2 hours to setup time!

[bill t.]

I had the VN4 cranked up to 120 psi, which is way too much.  That could barely drive a single 13mm nail into that 2" high moulding from Hell that needed three times that many nails on each stack.  Applying principles learned in industrial design 101, I ditched that moulding, and have lived happily ever after.

[Justan]

Something to be said about not locking horns when there are other solutions. . .

[Justan]

…the VN4 cranked up to 120 psi, which is way too much.

Not that I wish to belabor the point but fwiw, according to the AMP support tech I spoke with a couple of weeks ago the air psi going to the underpinner can be higher. He suggested 135 or > . This pressure goes to the v-nail driver. The built in pressure regulator controls what makes it to the clamps and other pneumatic bits. Running 135 psi to the clamps and other bits is too much for most wood and can dimple or otherwise damage softer media.

[jferrari]

according to the AMP support tech I spoke with a couple of weeks ago the air psi going to the underpinner can be higher. He suggested 135 or >.

I can sink a 16D common nail from a pneumatic framing nailer into 4" thick yellow pine with only 120psi. Needing 135psi to install a quarter to half inch long V-nail is ludicrous. Like Bill said the material must be too dense and just plain not worth messing with. It's also quite likely that running an underpinner at such a high pressure will cause undue stress and wear on the bumper inside the ram resulting in premature failure of said ram.  - Jim

[bill t.]

These guys wrote the book on hardwood moulding.  Read the first sentence in the part labeled "Nailing."

http://vermonthardwoods.com/joining_frames.asp

[Justan]

I can sink a 16D common nail from a pneumatic framing nailer into 4" thick yellow pine with only 120psi. Needing 135psi to install a quarter to half inch long V-nail is ludicrous. Like Bill said the material must be too dense and just plain not worth messing with. It's also quite likely that running an underpinner at such a high pressure will cause undue stress and wear on the bumper inside the ram resulting in premature failure of said ram.

Thanks for the comments. I’ll go with the recommendations of a factory trained technician who is employed by AMP. The condescension and baseless conjecture offered by you is a joke.

These guys wrote the book on hardwood moulding.  Read the first sentence in the part labeled "Nailing."

The people at AMP wrote several books on underpinners, commonly referred to as product instruction manuals, plus they design, build and support their tools. You can follow the rationalizations of random wood workers who support a theory you like, if you want but I’ll go with what AMP suggests as they actually know something about their tools. Sorry if that detail is lost on you...

[huguito]

Hi Bill
In the same article they mentioned colored waxes to finish up not too perfect joints.
Any brand in particular? Hopefully something that can be found in Lowes or Home depot

[jferrari]

Not that I wish to belabor the point (but you did anyway, what are supposed to believe?) but fwiw, (it's worth less than nothing, read on) according to the AMP support tech I spoke with a couple of weeks ago (there's the baseless conjecture) the air psi going to the underpinner can be higher. He suggested 135 or > . (I seriously doubt it and explained why in my last post)

Thanks for the comments. (You are welcome. I hope you'll learn something from them.) I’ll go with the recommendations of a factory trained technician who is employed by AMP. (So will I when I see these recommendations in writing from AMP not your baseless conjecture.) The condescension and baseless conjecture offered by you is a joke. (There's nothing funny about you irresponsibly spouting inaccurate third-party hearsay on a public that can adversely impact human safety!)

The people at AMP wrote several books on underpinners, commonly referred to as product instruction manuals, (in which they post that the maximum pressure is 100psi except for the largest machines which is 110psi) plus they design, build and support their tools. (Right! So they should know!) You can follow the rationalizations of random wood workers (or me, with over 40 years experience, 30 of which with pneumatics) who support a theory you like, if you want but I’ll go (YOU can do whatever you want just don't profess it in a public forum) with what AMP suggests as they actually know something about their tools. (They do, RTFM) Sorry if that detail is lost on you... Justan, what's lost here is that it is irresponsible to make unsubstantiated modifications to manufacturers specifications that could injure someone in a public forum . I don't know why you thought you needed to make it personal - with me it's merely safety first.

If you can convince your AMP technician to post an official addendum to the owner's manuals stating that it is safe to set the pressure to 135psi I'll bite my tongue. Until that time I maintain that is unsafe.

What would you do if I posted something like: "I was talking to a licensed electrician the other day and he said that you can hook up 110 volt power tools to 220 volts no problem."?   - Jim