Underpinner vs thumbnailer


CGF, Certified Grumble Framer
Mar 18, 2004
Kennett Square, PA
I need some advice. I'm opening an Art Gallery and custom Framing shop in September. My business partner and I have attended framing school and are in the process of purchasing equipment. We're debating between a used pneumatic underpinner VN4 and a new Thumbnailer. Even though the used underpinner costs a lot more, we don't want to decide by price. A few people told me that the pneumatic underpinner is more widely accepted by the framing industry than the thumbnailer. Can you please share your thoughts on this? Thanks!
No question. Get the underpinner.

I used to order chop sometimes wedged/ThumbNailed and even considered buying a Thumbnailer (or the Fletcher version.) Then I had a few frames come back with broken Thumbnails. They are, after all, plastic.

The underpinner will be faster and, while it won't work with every profile you encounter, it will work more often than the Thumbnailer. It will also be quieter* and cleaner.

*Unless you get a compressor that sounds like a jet on take-off.
We had a thumbnailer for a while. I ruined several frames because I would grind a little too far and come out the face. Hard to cover THAT up with putty!
I would vote for the VN4 underpinner, but be sure you are not buying a very old VN4 that was just a 2 position and not 3 postiion machine. The VN4 orginally was just 2 position and about 8 years ago was replaced by the 3 postion one. A two position one is worth considerably less than a 3 postion one.

Thanks, Ron. The only problem that my bus. partner has is that we were told once you join the moulding,if the corner is a little off there's nothing that you can do; whereas with the thumbnailer, you can move it around a little bit before the glue dries. However, someone told me that the VN4 has several adjustments that can be made to the "fence" to compensate...I'm not quite sure what a fence is though. I'm definitely wanting the underpinner but I have to convince my partner.
We have both a v-nailer AND a thumbnailer. Each has advantages and disadvantages, but I find myself using the vnailer more and more. It's quicker, can handle wider profiles, and when properly adjusted gives good, tight (square) corners.

No contest, the underpinner wins.

Thumbnailers are one step above a toy. The Thumbnails themselves are junk, the plastic is too cheap and the Thumbnails break, sooner or later.

I used a Thumbnailer for a few years, after about a year, people started bringing frame jobs back with the miters pulled completely open, only thing holding them together was the paper backing.

Fortunately for me, I also had an underpinner, which was our primary joiner. The only thing I used the Thumbnailer for was deep hardwoods.

It continues to bother me about just how many other jobs I have out there that have miters popped open.

I replaced my Thumbnailer with a Hoffmann Joiner. It's a similar idea as a Thumbnailer, except it's all grown up stuff that really works properly.

We have an underpinner that I have never seen elsewhere. It is a foot operated Cassiece, and I do mean FOOT, no air. I love it because I can "feel" the join and am able to apply pressure to bad moulding as I ease in the pins.
As for hardwoods, we order from Garrett Moulding in Santa Cruz (North American Hardwoods, made in USA) and they "Max" route for me. The max is more like a V pin in shape and holds better and doesn't break, even when you want it to.
The best part about the v-nailer, is that I can throw it into the back seat, and take it somewhere and don't need air.
Like Baer…I also use a Cassese foot operated underpinner my model is the C88…..I like the manual foot operated underpinners as they allow you to perfectly match the mitre and then ease in the V-Nail if there is a problem with the moulding i.e. like warping or bad routing etc………this is just a personal preference I do know many framers who use air underpinners and swear by them.

When I opened I bought a "lot" of used equipment. A Thumbnailer was one of the pieces in the lot. I also purchased a NEW CS89 underpinner with a JunAir silent compressor. I had been ordering wedged moulding for many years for my "at home" framing. I still have the Thumbnailer. $200 bucks plus shipping and it's yours! :D

Guess that tells you what I would suggest.
After you "route" out the moulding to accept the Thumbnail, you are left with much less surface area on the miter to hold the glue. I believe that V-nails provide a much stronger join.

My V-nailer (Pistorious VN-J) is a hand jobbie (no sniggers, please) which is, of course, much quieter than any Thumbnailer.
Leave it to us sods to use our feet to frame with.
As for the "Blow" boys, I know more than a few
who swear by their tools. And swear at them, swear about them, and swear because of them....
Their kinda like a shovel. I've worn out many shovels in my time, but I never founda one I liked.
PS: Do they still doll up the cows with all the flowers and such for fair time?
Thanks for all of your help and suggestions. We took your advice and just bought the used Cassese manual underpinner. If we like it and decide that we eventually want a pneumatic one, we can buy one later. Thanks, again.
I had an emergency repair come in yesterday.

It was a large matted print, on the order of 34x44, with glass. The bottom rail was loose. It's for a retirement presentation tomorrow. Thankfully, it was framed elsewhere.

Turns out, the only thing holding the bottom rail in place (sort of) was the paper dust cover. There were two plastic Thumbnail wedges in each corner and all four of the bottom ones had broken in half. The glue alone was unable to hold the thing together, partly, as Ellen mentioned, because there was a lot less gluing surface to work with after the frame was routed for the Thumbnails.

I sanded the miters, re-glued them and inserted new Thumbnail wedges. Then I nailed it (hoping to avoid putting brads through the wedges.) After the dust seal was in place, I added WallBuddies and put a pair of steel braces on the bottom corners.

Marjorie, you made the right choice.
I don't use either...preferring a drill, glue and brads. I know it's slower, but my customers tend to like the old world ways. The old tap-tap of a hammer and the buzz of a saw in the visible back room has a certain charm also.

Some mouldings do demand underpinning, but my local distributor will join frames for free if you order at least three at a time. Also offer free delivery once a week.

They have a Wizard cutter. If it's multi-opening double mats with V-grooves, etc., I don't mess with it. Let the computer do the fancier stuff.
My time is more valuable doing other tasks...not to mention the distasteful language I might use if I screw up on the last cut.

I use to feel that it was not "custom craftsmanship" if a computer cut the mat. Then I remembered how my grandfather use to cut mats with a sharpened knife and a beveled straight edge. He progresseded to buy a Keeton Cutter, but still cut beveled ovals free-hand.

I am fortunate to have such a good distributor locally.

Dave Makielski
Thanks, Ron. The only problem that my bus. partner has is that we were told once you join the moulding,if the corner is a little off there's nothing that you can do; whereas with the thumbnailer, you can move it around a little bit before the glue dries.
You can eliviate that concern if you build your frames in vises first; I have 4 free-standing vises which I set the frames in, glue them and let them dry before underpinning them. When you put the legs in the vises, it's easier to hone in and get a nice clean join with no gaps or steps. And you can spot problem corners if you set them in the vices first and notice that one has to be sanded down a touch or that a leg is warped before you end up joining three corners and cursing at the fourth...
Thanks, everyone, for your advice and sharing. The underpinner arrived two days ago. It's 2 months and 20 days til our preview party (9/10) and we'll be open for business on 9/11. It's beginning to "sink in" about now. We have all of the equipment that we need and are getting ready to order the supplies. We'll be painting, carpeting, decorating, and building storage, displays, etc. from now til then. We'll also be practicing, practicing, practicing. It's scary but so exciting. Keep your fingers crossed for us.....pleeaassseee!
Marjorie, welcome to The Grumble and the joys of being self employed. You will do just fine if you love the craft and understand the real secret for success in any business. Her it is, never quit, no matter how bad it gets, it will always get better, then worse, then better then worse, then better..........then.... etc,.........etc.