Plywood prep before cutting?

[Joe W.]

The Learning Continues        

I decided to make this (see below) Steve Good pattern for my son-in-law.  He’s a mechanic and  particular about his tools, so this is going to be a birthday present for him. 

I enlarged the pattern to 200 percent, so it’s 14” by 18”.  Cut it out using ¼” Birch plywood purchased from one of the box stores.  Used Pegas #2/0 and #3 ST blades.
If I counted right, it was only 91 holes, but as soon as I sat down to start cutting, I found myself uncomfortable, anxious, and a little worried. 
This is the first time cutting something this size and it really threw off when it came to placing my hands to move the wood for cutting out all the letters.  I managed, but it was slow going, and I don’t think I got comfortable until the last letter was cut out.  The hardest letters to cut out were the ones nearest the edges as it meant a large portion of the wood at times was sticking out in front of the machine and me.  Whew!  I don’t know how you folks do it, but I’m all ears for any thoughts or suggestions you may have for cutting large pieces.
But wait, there’s more . . . then I moved on to taking the pattern off and, as you can see at the bottom left, a shard piece of the plywood came off with the shelf liner paper.  Wasn’t expecting that as it never happened before.  I have the piece and will glue it back in.  As soon as I discovered that, I got out the mineral spirits, but that didn’t do much good, so then got the heat gun and that worked well.
The pattern was sprayed with 3M 77 adhesive and placed on top of the shelf liner I had placed over the plywood. Again, first time the shelf liner didn’t peel off easily.  May have been because if was on for several days.
After cutting, I moved on to sanding the fuzzies off on the back and used a small file.  When I turned it back over, I saw a few small spots where the top layer of plywood came off.  ARGGHHHH!
I was going to fill in the letters with polymer clay, but at this point figured it was time to call on the long-timers for opinions/suggestions/jokes/etc.
Questions: 
1. would putting on a coat of shellac, lacquer/poly before cutting prevent or lesson the tear out I experienced?
2.  Or should I have just used a solid piece of wood?
 

Oh, and while the lettering doesn’t look the greatest up close, it does look OK when viewed from 3 feet or more away. 
 

 

[FrankEV]

Your very first mistake was using 1/4" Birch Plywood from a box store.  Although the vaneer is Birch the plywood itself is not a very well laminated/glued up product and is very suceptible to fraying, peeling and delaminating.    For dencent cutting the plywood must be a quality porduct.  HD sells 2'X4' sheets of real BB PLY, as well as other species, but at about 3X the price of their typical birch ply.  A quality brand solid core product is a much more suitable product.

IMHO, the only thing needed before applying the shelf liner is a good sanding to a very smooth finish.  I may go overboard, but I sand to very smooth with 600/1500 grit before applying the liner.

If fuzzies on the back side were very prolific, it is another indication of poor quality plywood.    Some fuzzies are always going to be there but are easily remooved by sanding and then using a butane torch to get them out of the small pointed cuts.

And, again only in my opinion, for a sign like this I would have probaly used a good  1/2" sanded ply and applied a 1/8" backer, assuming the sign would be finished with a good quality paint for hanging in a shop environment. 

Oh, and BTW, the cutting looks fine.

   

Edited March 8, 2021 by FrankEV

[Scrappile]

Frank provided great info... I sand the piece before applying the pattern, but not nearly as much as Frank does... And I bet if you looked close at one of my pictures versa Frank's you probably could tell the difference for sure... I use an orbital sander and 220 grit..  But good enough for me,,, I don't sell so, well I am also lazy..  I also glue the pattern directly to the wood... No tape, no shelf liner... I have tried all of those and just could not see the advantage... But it is personal preference..  BUT I do use real Baltic Birch plywood of the best grade I can find.  You will not find it at the big box stores... I go to Windsor Plywood, (local) and it is hit and miss.  They sell the BB but not always the best grades..  Lately it has been mostly miss..  A lot of limber stores (not the big box ones) also sell BB.   Pays to shop around..

AND,, you did do an nice job cutting you sign.... I like.. Should do one for my shop..

Edited March 8, 2021 by Scrappile

[FrankEV]

9 hours ago, Scrappile said:

... I use an orbital sander and 220 grit.. 

JFYI.  I have two palm sanders pre-fitted with sand paper and plugged in for immediate use.  One w/220 grit and the second w/ either 600 or 1500, depending on which I grab out of the package (both produce almost the same result).

A typical panel takes about a minute or so with the 220 and then about the same for the finer grit.  You can actually feel how smooth the panel gets after using each.  With a very  smooth finish I have never gotten any tear out while using either the BB Ply panels or the Solid Core Plywood intended for laser cutting as sold by HD in many various species (I predomently use the Maple and Walnut).     

I do use the box store ply products ocassionally for backers when I need something larger then 12" wide.  

  

 

[TAIrving]

Nice cutting.  Your son-in-law will like that! 

You mentioned trying to use mineral spirits to help remove the shelf liner.  Depending on the shelf liner, that will not work as the mineral spirits will not penetrate the shelf liner to get to the adhesive.  The heat gun was a better solution, but did it leave a sticky residue?  

[Joe W.]

21 minutes ago, Algae said:

The heat gun was a better solution, but did it leave a sticky residue?  

No, I got lucky there. 
I've seen previous posts that mention good results with using letter size adhesive label sheets: 
https://www.onlinelabels.com/products/ol177wx?qty=100&src=mp-1&utm_source=googleproductsearch&utm_medium=productsearch&utm_term=ol177wx&utm_content=100sheets&utm_campaign=productsearch&gclid=Cj0KCQiAs5eCBhCBARIsAEhk4r6cFWnRl4-DmWstOY7E5SNgbav2B0k2entFIDVcV9U_bPECr57UXbIaAhJiEALw_wcB

and I think I'll give that a try (I just used up the shelf paper I got when I started scroll sawing).

[BadBob]

For plywood, I glue the pattern directly to the wood with 3M77 and soak the paper with mineral spirits to remove. If you wet it well enough, the pattern will come right off and leave little residue.

The downside is that you may need to clean some of the adhesive off of the wood. If you don't get it all off, it could interfere with any finish you apply.

They do make a low-tack tape, but I have not used it.

[new2woodwrk]

Good advice so far.

Here's what I learned from this forum's experts when I first started (I consider myself a beginner compared to these folks)...

• Quality wood is imperative - simply because using low quality wood (big box store junk) you can't really learn whether it's your technique or the wood that is the problem. More often than not it's the wood! This is perhaps one of the best lessons I learned from these guys/gals. Cheaper is not always better, in fact it seldom is better in the long run.
• 3m 77 - very potent adhesive, I use 3m 45 and makes a huge difference in removing patterns/shelf paper.
• Which shelf liner are you using? - I use Duck brand exclusively. There are a few threads about this. I've tried other brands with terrible results. Removing the pattern often removed some of the wood.  Not good
• Sand the wood before you put down the shelf paper or tape which ever you use. I use tack cloth after I sand to make sure no dust is left behind. Makes a huge difference in how the paper adheres to the wood.
• I use a scraper when placing the shelf paper - this ensures I get out air bubbles and keeps the paper smooth. Helps with the cutting.

Hope that helps somewhat

 

 

[Joe W.]

8 hours ago, FrankEV said:

. . . the Solid Core Plywood intended for laser cutting as sold by HD in many various species (I predominantly use the Maple and Walnut).       

  

 

Hi Frank,

thanks for your thoughts and suggestions.  
I looked at the HD website and found this - wanted to check with you and see if this is what you were referring to:
Columbia Forest Products 1/2 in. x 2 ft. x 4 ft. PureBond Maple Plywood Project Panel (Free Custom Cut Available)-1802 - The Home Depot

And thanks for your words on the lettering.  

[Joe W.]

5 hours ago, new2woodwrk said:

Good advice so far.

Here's what I learned from this forum's experts when I first started (I consider myself a beginner compared to these folks)...

• Quality wood is imperative . . . .
• 3m 77 - very potent adhesive, I use 3m 45 and makes a huge difference in removing patterns/shelf paper.
• Which shelf liner are you using? -
• Sand the wood before . . . 

Hi Jes,

Yeah, Roger that on quality wood.  Guess it's time to dive in and get some good stuff.
I just returned from getting a can of the 3m45.  Was initially using Kryon Easy Tack and ran out of that, so I grabbed the 3m77 I had on hand and used that for the pattern.  I won't be doing that again!
And I picked up another two rolls of the Duck brand shelf liner from WalMart.  I was surprised to see how quickly I used up the initial roll.  
I hadn't been sanding first before putting it on, but after reading you, Frank and Scrappile's posts, I will be adding that to my process.

[Joe W.]

20 hours ago, Scrappile said:

AND,, you did do an nice job cutting you sign.... I like.. Should do one for my shop..

Thanks Paul,

I was thinking about filling the letters in with Polymer clay, but after the experience with the thin surface ply flaking off, I'm just going to use a colored backer.  
This was my first time cutting this large a piece and it makes me even more impressed with the pieces I've seen on SSV. 

[new2woodwrk]

12 hours ago, Joe W. said:

Hi Jes,

Yeah, Roger that on quality wood.  Guess it's time to dive in and get some good stuff.
I just returned from getting a can of the 3m45.  Was initially using Kryon Easy Tack and ran out of that, so I grabbed the 3m77 I had on hand and used that for the pattern.  I won't be doing that again!
And I picked up another two rolls of the Duck brand shelf liner from WalMart.  I was surprised to see how quickly I used up the initial roll.  
I hadn't been sanding first before putting it on, but after reading you, Frank and Scrappile's posts, I will be adding that to my process.

Are you using the 12" or 18" shelf liner and is it the clear?

Make sure you are getting the Duck EasyLiner Adhesive - there are 2 different kinds of liners and the Easyliner is by far the better of the 2.

One roll should last a significant number of patterns.

I use both the 12" and the 18" when prepping my wood for patterns.

Mind you I buy 15-16 feet boards cut in half with a minimum width of 8",  I usually get around 10-12" widths, and don't do ply wood cuts anymore (at least not at the moment)

I use the 18" placed across the board to the end, and then fill in the end with the 12"

I can usually get 36 patterns out of a roll my cost... $16.31/ 36 = $.45 per pattern

 

Edited March 9, 2021 by new2woodwrk

[Joe W.]

1 hour ago, new2woodwrk said:

Are you using the 12" or 18" shelf liner and is it the clear?

Yep, got the 18" and it is clear - there were only two rolls on the shelf, so I bought both of them.  Always nice to have extra on hand.

[Scrappile]

Okay 

On 3/7/2021 at 7:23 PM, Scrappile said:

Frank provided great info... I sand the piece before applying the pattern, but not nearly as much as Frank does... And I bet if you looked close at one of my pictures versa Frank's you probably could tell the difference for sure... I use an orbital sander and 220 grit..  But good enough for me,,, I don't sell so, well I am also lazy..  I also glue the pattern directly to the wood... No tape, no shelf liner... I have tried all of those and just could not see the advantage... But it is personal preference..  BUT I do use real Baltic Birch plywood of the best grade I can find.  You will not find it at the big box stores... I go to Windsor Plywood, (local) and it is hit and miss.  They sell the BB but not always the best grades..  Lately it has been mostly miss..  A lot of limber stores (not the big box ones) also sell BB.   Pays to shop around..

AND,, you did do an nice job cutting you sign.... I like.. Should do one for my shop..

Okay, I remembered another great reason for my method of no tape, no shelf liner.  When I am done scrolling a piece, I remove the pattern using Mineral Spirits... soak a minute and pull the pattern off.... Most times the pattern comes on in one piece.... let it dry and the spray with a little adhesive and decorate you cabinet door and shop walls with your used patterns... what do you think?? 

 

Edited March 10, 2021 by Scrappile

[Joe W.]

Wow!  Brilliant!!! 
I think you are one smart man.
You remind me of an uncle I had . . .  He got double use out of everything he touched and for that was very well off.
Thanks for sharing.

[FrankEV]

On 3/8/2021 at 6:18 PM, Joe W. said:

Hi Frank,

thanks for your thoughts and suggestions.  
I looked at the HD website and found this - wanted to check with you and see if this is what you were referring to:
Columbia Forest Products 1/2 in. x 2 ft. x 4 ft. PureBond Maple Plywood Project Panel (Free Custom Cut Available)-1802 - The Home Depot

And thanks for your words on the lettering.  

Yes, amoung the other CFP sizes and thicknesses.  The PureBond solid core  ply is a very high quality product with very good vaneers and there are no voids.

[crupiea]

i think it looks great.  

here is my take on it what might help. 

For gluing on the paper. I use 3m 77 spray.  Right onto the back if the pattern. Set a timer for 3 minutes then attach to the wood,.  Stays on when I need it to stay on and peels right off when done. Now pulling or hassle. 

3 minutes is the key with this type glue.  

As for the letters, I stopped cutting them out of the piece all together and cut them out from scrap and glue them on.  Way simpler this way and if one gets messed up, i toss it and cut another one.  Makes these big projects way simpler. 

Have noticed that the grain going up and down seems to keep the letters from having tiny blow outs.  Side to side grain seems to always be trouble for me. 

[Roberta Moreton]

On 3/8/2021 at 8:57 AM, Joe W. said:

No, I got lucky there. 
I've seen previous posts that mention good results with using letter size adhesive label sheets: 
https://www.onlinelabels.com/products/ol177wx?qty=100&src=mp-1&utm_source=googleproductsearch&utm_medium=productsearch&utm_term=ol177wx&utm_content=100sheets&utm_campaign=productsearch&gclid=Cj0KCQiAs5eCBhCBARIsAEhk4r6cFWnRl4-DmWstOY7E5SNgbav2B0k2entFIDVcV9U_bPECr57UXbIaAhJiEALw_wcB

and I think I'll give that a try (I just used up the shelf paper I got when I started scroll sawing).

When I use full sheet labels I NEVER apply it directly to the wood. Always clear shelf liner first. It wouldn’t come off for me otherwise. 
You are correct when you stated the shelf liner was left too long. You also need to sand at least to 220. 

[Rockytime]

On 3/10/2021 at 4:00 AM, FrankEV said:

Yes, amoung the other CFP sizes and thicknesses.  The PureBond solid core  ply is a very high quality product with very good vaneers and there are no voids.

Where do you get PureBond plywood? Is it different than Russian Baltic Birch?

[FrankEV]

8 hours ago, Rockytime said:

Where do you get PureBond plywood? Is it different than Russian Baltic Birch?

Home Depot.   Yes, the core is different and the vaneer is a little better quality.

The 10 pack of Maple panels have been out of stock for some time now.