# Best technique for cutting large slots in Baltic Birch plywood?



## Camasonian (Mar 18, 2021)

Hello everyone. I'm helping my daughter make a folding bed platform to insert into the back of her SUV for camping. I'm thinking of using 3/4" Baltic Birch plywood but I'd like to cut a bunch of 2-3" wide slots in the plywood for ventilation and to reduce the weight.

What would be the easiest way to accomplish this and wind up with something that looks like this photo?

I have a table saw, sabre saw, router, and router table. I'm just not sure about the most efficient way to cut about 20 slots into 3/4" Baltic birch.

Any suggestions?


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## MrUnix (May 18, 2012)

I'd use a router and template.

Cheers,
Brad


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## AlanWS (Aug 28, 2008)

To make the slots, I'd use a hole saw at each end, then remove the bulk of the material with a jigsaw. Then using a template and router with a pattern bit I'd clean it up.

The question would be how to efficiently lay it out and keep it all aligned. I might use a long clamped on straightedge to position the template. Attach it down, perhaps with brads. If you don't want brad holes, make it long enough that the brad holes go into what will become the next slot. The last slot can give clamp access. After the template is in place, I'd drill, then use the jigsaw with a support block on one side so the template remains in position as a guide, then rout and move the template to the next position.


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## SMP (Aug 29, 2018)

Honestly, unless you want to do this as some type of "challenge", i would just completely change the design. For example instead just make x number of slats, with a couple strips of nylon webbing running perpendicular to the slats and stapled. Faster, easier, way more portable etc.


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## splintergroup (Jan 20, 2015)

+1 on the router and template, but the jig saw approach would be nice to trim close to the template and spare some time and a whole bunch of wear on your (needs to be carbide) bit.


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## Wood_Scraps (Jan 31, 2021)

I suppose it depends whether you're going for both form and function. If function is the primary aim, a stencil and jigsaw would be easy and super quick. If appearance matters, adding a router and template to the mix would make sense; as Alan suggests.


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## JIMMIEM (Feb 5, 2016)

I'd use a jig saw to cut out the bulk staying within the final outline. Then a router and template, Then a router with small radius roundover bit to ease all the edges.


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## Camasonian (Mar 18, 2021)

> Honestly, unless you want to do this as some type of "challenge", i would just completely change the design. For example instead just make x number of slats, with a couple strips of nylon webbing running perpendicular to the slats and stapled. Faster, easier, way more portable etc.
> 
> - SMP


It's not going to be a bed frame in a house. It will be a folding platform to put in the back of an SUV to convert the cargo space into a camper platform (with rolled out memory foam cot mattresses on top). I'm thinking the dimensional rigidity of Baltic birch plywood will be better than building up some traditional wood frame that will requires edges that won't fold.

I'm visualizing 4 sections of 3/4" Baltic Birch plywood in 48" x 18" inch planks that are attached with piano hinges or similar that unfold to form a 48" by 72" sleeping platform. The slots or holes would be to reduce the weight and allow more air circulation. Alternatively I could just drill a whole bunch of holes.


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## Loren (May 30, 2008)

I might rough out the hole with a jigsaw and then use a router template to get the shape wanted. Less dust that way and probably quicker. Not all jigsaws are equal and some cut straighter than others and of course a sharp blade is worth having.

All said, this is CNC type work and unless you're doing it as a challenge, as mentioned above, there are alternate means of doing something that achieve a similar effect.


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## 1thumb (Jun 30, 2012)

> I m visualizing 4 sections of 3/4" Baltic Birch plywood in 48" x 18" inch planks that are attached with piano hinges or similar that unfold to form a 48" by 72" sleeping platform. The slots or holes would be to reduce the weight and allow more air circulation. Alternatively I could just drill a whole bunch of holes.
> 
> - Camasonian


Whats going to support the piano hinged baltic birch?


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## Camasonian (Mar 18, 2021)

> I m visualizing 4 sections of 3/4" Baltic Birch plywood in 48" x 18" inch planks that are attached with piano hinges or similar that unfold to form a 48" by 72" sleeping platform. The slots or holes would be to reduce the weight and allow more air circulation. Alternatively I could just drill a whole bunch of holes.
> 
> - Camasonian
> 
> ...


The folded down seat backs, center console, and some kind of removable frame. I haven't worked out all the details.

Has to be folding in order to get it into the vehicle and operate the vehicle with the rear seats up. There are a bazillion ideas for converting small SUVs into camper bed platforms all over the internet but they are mostly just made by young folks with no woodworking skills just hacking things together with fir plywood and 2×4s. I'm trying to come up with something more elegant.

It has to be folding in order to drive the car when not in camping mode. And get the thing into the back as the rear hatch opening is smaller than the cargo area.


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## SMP (Aug 29, 2018)

> It s not going to be a bed frame in a house. It will be a folding platform to put in the back of an SUV to convert the cargo space into a camper platform (with rolled out memory foam cot mattresses on top). I m thinking the dimensional rigidity of Baltic birch plywood will be better than building up some traditional wood frame that will requires edges that won t fold.
> 
> - Camasonian


Right. Which is why I would do webbed planks, that way you can roll it all up into a nice tight roll that can fit behind a seat etc. And you can make a frame that folds easier than a bunch of big sheets.


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## Lazyman (Aug 8, 2014)

Camping bed you say? I would look at something like this. I stumbled upon this several years ago. 

























More pictures here.

Looks like the plans can be purchased here (not vouching for the seller).

EDIT: I just looked at the plans more closely and the one pictured above appears to be the full size plan.


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## Camasonian (Mar 18, 2021)

That's an interesting idea. The car is my daughter's Kia Soul and she wants to set it up for car camping this summer. I was thinking something more like this fancy unit from Korea but without all the pull out shelving underneath. And with the bed boards cut out to reduce weight


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## 1thumb (Jun 30, 2012)




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## therealSteveN (Oct 29, 2016)

Forstner bit for 2 round holes at each end, cut the straight sides with a jigsaw. If you didn't like the looks of it, then just trim them out a bit bigger with a template, and a router. The hardest work would be measuring out the grid, so they had even spacing.


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## Kudzupatch (Feb 3, 2015)

I would just drill holes, skip the slots.


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## craftsman on the lake (Dec 27, 2008)

If you drill them and cut them by hand it's going to be a lot of work unless you want to leave them rough. The plunge router and template is the way to go. Once you've got the template made the each slot will be quick.


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## wapakfred (Jul 29, 2011)

I join with those that would cut holes at each end and jigsaw the bulk out, then use a template and router with flush trim bit to clean things up. Should you choose to do this, mark centerlines on the template, and of course centerlines on the workpiece to make lining things up a whole lot easier.


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## waho6o9 (May 6, 2011)

+1 drill holes to make a Fibonacci symbol


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## tvrgeek (Nov 19, 2013)

I too question the support. I would have to see the SUV to know what it is sitting on. FWIW, my bed is on 1/2 inch plywood. 3/4 may be overkill. The mattress spreads the load. Is the floor of the SUV not flat enough to support a mattress? Even my old Saab 900 made a great bed with just a bit of foam.

The folding design you envision I think would be very heavy.


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## Lazyman (Aug 8, 2014)

That's a cleaver bed in the Kia. My only concern is what do you do with all of the other stuff you have in your car while sleeping. She might need some sort of water and varmint proof boxes too.

As Kudzu mentioned, you could just drill a bunch of holes with a hole saw and use a router to do a roundover to reduce the weight and not worry about the slots. Might even be stronger that way.


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## Camasonian (Mar 18, 2021)

> I too question the support. I would have to see the SUV to know what it is sitting on. FWIW, my bed is on 1/2 inch plywood. 3/4 may be overkill. The mattress spreads the load. Is the floor of the SUV not flat enough to support a mattress? Even my old Saab 900 made a great bed with just a bit of foam.
> 
> The folding design you envision I think would be very heavy.
> 
> - tvrgeek


The problem with the Kia Soul is that it is a pretty small car. The rear cargo area behind the rear seats is about 20" long so pretty small and not much space for anything other than some groceries. When the rear seats are folded down it creates more flat space, but it is not level. The folded seats sit about 2" higher than the cargo area further rear and they provide total length of about 4' of space. To get a full 5' 6" of space you need to push the front seats all the way forward and then lean them forward.

So a sleeping platform has to span 20" of flat stable cargo area, 25" or so of uneven folded down rear seat backs, and another 20" of open space between the rear seat and front seat.

The logical way to do that is to create a stable platform in the rear cargo area, and a stable platform resting on the floor between the front and rear seats, and then have some sort of frame that connects the two supports upon which the flat sleeping platform can sit.

The other problem is that the rear hatch is only about 45" wide on the diagonal but the cargo area and interior is 48-50" wide so you can't fit a large platform into the car. It has to be in smaller pieces or folded up so that you can put them in lengthwise through the hatch and then position them once inside the car.

This would be WAY easier with a larger SUV or minivan that has a flat 4×8 space in the rear and a larger hatch opening. I used to carry 4×8 sheets of plywood in my Toyota Sienna so that would have been a super easy car for this sort of thing. Unfortunately my daughter has a Kia Soul so it makes the puzzle more complicated. She could just trade it in for a larger SUV but we want to avoid that cost and hassle and see if we can make this work for her for when she wants to do car camping adventures.

She has a Yakima roof box that she can use for most of her gear. So I'm not particularly worried about that. It will be a tight squeeze, but you are only 22 once in your life.


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## Davevand (Feb 10, 2016)

I would be careful cutting big hole or slots for memory foam. Memory foam has no support and would just squeeze thru big holes or slots and be very uncomfortable to sleep on. I think I would go with a support structure and a 1/4 inch sheet of plywood for the base (with lots of small holes for ventilation if needed)


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## SMP (Aug 29, 2018)

With all the new rooftop tents available now, that would be my choice unless i had a full size SUV.


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## bndawgs (Oct 21, 2016)

The Bourbon Moth guy recently outfitted a car with some removable camping stuff.

Check it out.


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## Camasonian (Mar 18, 2021)

> With all the new rooftop tents available now, that would be my choice unless i had a full size SUV.
> 
> - SMP


Yes, perhaps if one was only visiting actual campgrounds. Right now she is working at a ski resort and meeting all these co-workers who basically live out of their cars doing summer rafting and surfing jobs and is thinking about the same idea. So the ability to stealth camp in your car is what she is aiming at. For actual car camping at campgrounds she can just use a tent anyway. The other problem with rooftop tents is that you lose your Yakima box storage for the snowboards and other gear.

She basically wants to be able to comfortably stealth sleep in the car and then still use it during the day.

What she really needs is a van but that is a pile of money and I don't know how long this lifestyle is going to last. She just graduated from college with a degree in travel PR and marketing and is kind of just waiting out the pandemic for when travel industry jobs start coming back to the cruise lines, airlines, big hotel chains and resorts and such.

Anything I can do to help her live the adventure and not boomerang back to her childhood bedroom is a good thing in my book!

I am now thinking that maybe Baltic Birch in 1/2" thickness might be more than adequate with just smaller ventilation holes drilled to reduce the condensation. I don't have any sheets of it around the garage to get a sense of how stiff it is compared to ordinary fir plywood but I'm guessing it is better than ordinary plywood.


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## Andybb (Sep 30, 2016)

> I d use a jig saw to cut out the bulk staying within the final outline. Then a router and template, Then a router with small radius roundover bit to ease all the edges.
> 
> - JIMMIEM


Yep.


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