PG warp going from wet to dry climate


#1

My brother and I have been collaborating on engraving some fine art drawings (his) on to PG plywoods. I did some smaller ‘sample’ sizes and sent them off to him. He mentioned during our phone conversation yesterday that those samples have already warped coming from damp Oregon to dry New Mexico. We are wondering if gluing them completely onto another larger piece of PG would help curtail the warping? My other thought was, would it make any difference if the engraved piece had the grain going one way and the second piece (the gluee, if you will) had the grain going the opposite direction?

Any and all thoughts and suggestions will be most appreciated.


#2

I had some :proofgrade: warp on me. I laid a couple of books on it for a couple of days and it became (relatively) flat again. But I know next to nothing about woods and how to work them. :slight_smile:


#3

Check out https://glowforge.com/support/topic/troubleshooting/proofgrade? (Note: must have access to the app to view).


#4

I read the troubleshooting notes that Dan linked for me, and there are many good ideas and tips in there. The problem is going to be because of the difference in climate and not that the PG materials were warped to begin with. If someone were to purchase an engraved work of art, it would not be cool at all if it began warping afterward. Could be that there’s no solution for this situation. Thanks for all input.


#5

If you go the route of gluing two pieces together, rotate one so the grain is 90 degrees in relation to the first. It’s what they do with plywood (alternating grains) to make it more resistant to warping :slight_smile:


#6

Thank you…that’s sort of what we were thinking, but knowing nothing about things like that, I very much appreciate your input. :slightly_smiling_face:


#7

I was just looking at the catalogue for the first time too, and I see that they have proofgrade plywood. That might be more economical to try out than using two pieces of hardwood proofgrade :slight_smile: Inherently, ply will be more stable and resistant to warping, but the edges show the layer construction. You can get veneer to cover that up, and then trim it, if it’s an issue. I’m super excited to start working on these sorts of things myself (THE EMAIL came last week), so I’d be interested in your results!


#8

emphasis mine

Since the engravings appear to have been on PG plywood in the first place, I’m not sure what effect (if any) gluing two cross-grain pieces would have, but it’s worth a shot.

Since I live in a dry climate, almost all the PG woods I’ve received have been warped to some degree, so I put them at the bottom of the stack and let the weight of the “older” wood press 'em flat. :wink:

A few of my pieces have warped after engraving (some spectacularly), but flattened out after a few days. It might be that your brother’s pieces might be ok after a bit of a rest – flat with a weight on it, if possible.

Keep us posted – would love to hear how this turned out.


#9

Really good catch @dwardio. I would assume that the more layers, the stronger the structure, the more resistant to warping, but it does make my follow up post pointless :slight_smile:


#10

yes, except that proofgrade “plywood” isn’t that kind of “plywood”. Proofgrade has the veneer layer (grain goes long-ways) an mdf layer, and another veneer layer that again goes long-ways. There is not cross ply.


#11

D’oh, palmsmack! :flushed:


#12

These things happen when a commonly-used word or term is stretched outside of its common use.

Plywood is a sheet material manufactured from thin layers or “plies” of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which includes medium-density fibreboard (MDF) and particle board (chipboard). -wikipedia

see also “shipping”, “crowd-funded”


#13

As I understand it the warping should be coming from water leaving (or entering) the material unevenly. If the material is kept flat during this process you should be good once it has stabilized in the new climate. If you live in a climate with swings in humidity levels…

What I’m trying to say is, “have you considered securing it in a frame?”


#14

someone on one of the FB forums posted a neat trick a little while back;
routing a slot the thickness of your (warped) material into pair of 2x4s.


#15

I agree with @jbv here, and another thought might be to glue it down on a piece of NON proofgrade plywood. Since you are working small, and aiming for an “art” customer, you might want to look at something nice like http://www.rockler.com/24-x-48-maple-plywood


#17

These were going to be sort of self-framed, if there is such a thing. Not sure I can explain it. Engrave and cut out, then fastened onto another piece of wood with an extra 1.5” around it…like a matte frame…maybe scored around the edge.


#18

Sorry, my bad in the use of frame. I was thinking of a frame to lock it down and prevent warping during shipment and even storage as it acclimates to New Mexico. Not the presentation/decorative frame.


#19

Thank you…I’ll check that out. I will be sharing all these thoughts and comments with my brother and I will keep everyone posted about our experiments.


#20

Oh…I understand. These are quite small though, so it could be overkill. They are maybe 4-8” tops. Some are square and some rectangles.


#21

That just means the frames will require less additional postage.