Foamie floor

Canvas covered foamies (Thrifty Alternatives...)

Moderator: eaglesdare

Re: Foamie floor

Postby Tyrtill » Sat Jun 20, 2020 10:16 pm

I can’t tell you for sure the thickness its either 1 1/2” foam or 2” foam. Looking at it I think its the 2” but I’m not sure.

With this foam its minimum 25psi crush so it will dent with point loads like elbows and knees however I would guess even a thin layer of wood or fiberglass would prevent that. Probably even a thick carpet pad or blanket.

If you are doing a full wrap it should do a 16” span. One of the negatives of fiberglass vs pmf is that if it bends much at all the fiberglass will crack where the pmf will allow flex.

Another work around might be to put foam ribs on the bottom to take up space between the floor and the roof of the vehicle and then it will still be light and allow you to reduce your unsupported spans.

You mentioned that the aluminum frame would be in from the edges. I don’t think the foam will cantilever well so make sure you test that.
Tyrtill
Teardrop Advisor
 
Posts: 83
Images: 14
Joined: Tue Mar 19, 2019 4:36 pm

Re: Foamie floor

Postby gregkn73 » Sun Jun 21, 2020 5:46 am

Tyrtill wrote:I can’t tell you for sure the thickness its either 1 1/2” foam or 2” foam. Looking at it I think its the 2” but I’m not sure.

With this foam its minimum 25psi crush so it will dent with point loads like elbows and knees however I would guess even a thin layer of wood or fiberglass would prevent that. Probably even a thick carpet pad or blanket.

If you are doing a full wrap it should do a 16” span. One of the negatives of fiberglass vs pmf is that if it bends much at all the fiberglass will crack where the pmf will allow flex.

Another work around might be to put foam ribs on the bottom to take up space between the floor and the roof of the vehicle and then it will still be light and allow you to reduce your unsupported spans.

You mentioned that the aluminum frame would be in from the edges. I don’t think the foam will cantilever well so make sure you test that.


The only reason I will opt for glass+epoxy instead of pmf, is the weight. Canvas is a lot heavier than 6oz/y2, and also I imagine it absorbs a lot more glue, than epoxy by fiberglass. Am I wrong?

Concerning cantilevering of foam , look at my scetch, I hope it isn't as bad as my description so far of the floor plan :-)Image
gregkn73
Teardrop Inspector
 
Posts: 19
Joined: Thu May 28, 2020 4:09 am

Re: Foamie floor

Postby TinkerTailor » Mon Jun 22, 2020 1:36 am

Hi everyone,

A quick note on fiberglass over foam and compression strength, knees, heels, etc.

I'm not a pro, but I have been shaping my own surfboards for over 20 years and have some experience there. Standard glassing schedule for the top or deck of a shortboard is one layer of 6 oz. and one layer of 4 oz. cloth. Often one of the layers will only cover the area of the deck on which you stand. The bottom of a board is typically glassed with one layer of either 4 oz. or 6 oz. cloth. Adding a gloss coat of resin over the laminating layer (as opposed to a sanded finish) may help resilience a tiny bit, but comes with more weight. Competition boards will have lighter glass and are considered semi-disposable, since professional surfers are sponsored by their surfboard manufacturers.

Even with the two layers of cloth over foam, dents from knees, heels, and even bony ribcages are so common as to be considered inevitable (referred to as "pressure dings" - dents that don't puncture the glass and thus don't break the watertight seal).

Since I hate sanding fiberglass more than I hate sanding wood, I have moved to vacuum bagging wood or cork skins over XPS foam for my boards. In my own experience, 1/8" plywood over foam is significantly more resilient in terms of compression strength than fiberglass, and laying up a sandwich panel for a floor would likely be simpler to construct as well as less expensive than to glass it.

If you're interested in the process for skinning a foam surfboard with wood skins, check out this blog post by the very kind master craftsman Grant Newby, whose process I now use Though I can't get hold of milled paulownia skins and use poplar bender ply instead. Might give foamie builders some interesting ideas!

https://woodensurfboards.blogspot.com/s ... vacuum+bag

TT
TinkerTailor
Teardrop Master
 
Posts: 106
Images: 149
Joined: Sun May 17, 2020 5:05 am
Top

Re: Foamie floor

Postby gregkn73 » Mon Jun 22, 2020 6:53 am

TinkerTailor wrote:Hi everyone,

A quick note on fiberglass over foam and compression strength, knees, heels, etc.

I'm not a pro, but I have been shaping my own surfboards for over 20 years and have some experience there. Standard glassing schedule for the top or deck of a shortboard is one layer of 6 oz. and one layer of 4 oz. cloth. Often one of the layers will only cover the area of the deck on which you stand. The bottom of a board is typically glassed with one layer of either 4 oz. or 6 oz. cloth. Adding a gloss coat of resin over the laminating layer (as opposed to a sanded finish) may help resilience a tiny bit, but comes with more weight. Competition boards will have lighter glass and are considered semi-disposable, since professional surfers are sponsored by their surfboard manufacturers.

Even with the two layers of cloth over foam, dents from knees, heels, and even bony ribcages are so common as to be considered inevitable (referred to as "pressure dings" - dents that don't puncture the glass and thus don't break the watertight seal).

Since I hate sanding fiberglass more than I hate sanding wood, I have moved to vacuum bagging wood or cork skins over XPS foam for my boards. In my own experience, 1/8" plywood over foam is significantly more resilient in terms of compression strength than fiberglass, and laying up a sandwich panel for a floor would likely be simpler to construct as well as less expensive than to glass it.

If you're interested in the process for skinning a foam surfboard with wood skins, check out this blog post by the very kind master craftsman Grant Newby, whose process I now use Though I can't get hold of milled paulownia skins and use poplar bender ply instead. Might give foamie builders some interesting ideas!

https://woodensurfboards.blogspot.com/s ... vacuum+bag

TT
Thanks a lot for your points, taken out by your experience with surfboards. Even though pressure dings, aren't of considerable importance, for the intended use of my roof top tent , do you think that a foamie floor wrapped with glass+ epoxy, covered 100% with a 10cm memory foam mattress, will it be as vulnerable as a surfer board, to pressure dings ? 10cm memory foam mattress, wouldn't protect it considerably? Thanks in advance for your thoughts.
gregkn73
Teardrop Inspector
 
Posts: 19
Joined: Thu May 28, 2020 4:09 am
Top

Re: Foamie floor

Postby John61CT » Mon Jun 22, 2020 8:06 am

Wow great stuff there!

But note that the **tensile** forces involved for surfing do not involve the board spanning a gap like sawhorses at the ends

yes of course there are stresses in use, but the board is well supported by a large surface area floating in water.

However having seen the diagram showing the slabs well supported by joists underneath, I am sure there will be few major issues.

Yes anything that spreads the weight load (psi) helps with puncture resistance and compression from point loads.
John61CT
1000 Club
1000 Club
 
Posts: 1958
Joined: Thu Nov 17, 2016 4:36 pm
Top

Re: Foamie floor

Postby tony.latham » Mon Jun 22, 2020 8:21 am

10cm memory foam mattress...


Not to hijack your thread, I hope that's deep enough. Ours is 20 CM. 12.5 CM medium density foam and 7.5 CM of memory foam. It's dreamy. Years ago we had an 8 CM foam mattress and it was too thin.

:thinking:

Tony
User avatar
tony.latham
Gold Donating Member
 
Posts: 6880
Images: 17
Joined: Mon Jul 08, 2013 4:03 pm
Location: Middle of Idaho on the edge of nowhere
Top

Re: Foamie floor

Postby TinkerTailor » Mon Jun 22, 2020 8:21 am

I imagine the mattress will definitely make pressure dents less likely and also less important, since they'll be covered up, etc. I wasn't taking that into consideration. Go for it if you prefer glassing!
TinkerTailor
Teardrop Master
 
Posts: 106
Images: 149
Joined: Sun May 17, 2020 5:05 am
Top

Re: Foamie floor

Postby Pmullen503 » Mon Jun 22, 2020 8:34 am

Are you going to have enough wood frame thickness to securely bolt your floor to the trailer? I would suggest you increase your framing to 3x3 cm. You said someday you may want to build a teardrop on top of your floor. You'll want something solid to attach your walls to.

What does your trailer weigh? Are you worried about saving a few kg on the floor when your trailer alone weighs 100 kg or more?
Pmullen503
1000 Club
1000 Club
 
Posts: 1103
Images: 67
Joined: Sun Nov 23, 2014 1:33 pm
Location: Fond du Lac, WI
Top

Re: Foamie floor

Postby gregkn73 » Mon Jun 22, 2020 8:46 am

tony.latham wrote:
10cm memory foam mattress...


Not to hijack your thread, I hope that's deep enough. Ours is 20 CM. 12.5 CM medium density foam and 7.5 CM of memory foam. It's dreamy. Years ago we had an 8 CM foam mattress and it was too thin.

:thinking:

Tony
I'm sure that 20cm will be a lot better. But since I want the rtt to have max outer thickness of 25cm to be aerodynamic enough, not to increase my car's diesel consumption considerable, 10cm matress is the max I can afford, so I can fit in there 2 pillows and 2 spread sleeping bags, when closed. 10cm matress also is a big step up in comfort, compared to self inflating camping mats, I used so far :-)
gregkn73
Teardrop Inspector
 
Posts: 19
Joined: Thu May 28, 2020 4:09 am
Top

Re: Foamie floor

Postby tony.latham » Mon Jun 22, 2020 8:54 am

I want the rtt to have max outer thickness of 25cm...


Gotcha.

Tony
User avatar
tony.latham
Gold Donating Member
 
Posts: 6880
Images: 17
Joined: Mon Jul 08, 2013 4:03 pm
Location: Middle of Idaho on the edge of nowhere
Top

Re: Foamie floor

Postby gregkn73 » Mon Jun 22, 2020 8:59 am

Pmullen503 wrote:Are you going to have enough wood frame thickness to securely bolt your floor to the trailer? I would suggest you increase your framing to 3x3 cm. You said someday you may want to build a teardrop on top of your floor. You'll want something solid to attach your walls to.

What does your trailer weigh? Are you worried about saving a few kg on the floor when your trailer alone weighs 100 kg or more?


If the RTT is something liked by family, I will consider to make an tear drop later, from scratch.

I would like the RTT as light as possible, ideally 20-30kg, because I want to mount and demount it, after each use. onto a trailer already existed and used for agricultural purposes or carrying my SIB for summer vacations. And alternatively mounted onto my car. I want to be light so I can mount it only when I want to use it and not permanently mounted onto either of trailer or car. All of the commercial RTT are not only crazy expensive but also crazy heavy 50-80kg!!! ,for this reason are mounted permanently onto cars, something I don't want. My intented use, at least at the beginning, is for myself for several 2-3 days ski mountaineering or kitesurf trips mounted onto my car and longer once or twice a year summer vacations with my family, mounted onto my trailer. Until now we camped in tents during summer vacations with my family and me into my car while skiing or under the stars when kitesurfing
gregkn73
Teardrop Inspector
 
Posts: 19
Joined: Thu May 28, 2020 4:09 am
Top

Re: Foamie floor

Postby Tyrtill » Mon Jun 22, 2020 8:57 pm

162310

The red parts are cantilevered and would probably snap the foam without either a lot more glass or a little support.

I would recommend running the wood the other way to support this cantilever or put some foam runners parallel to the aluminum along the edges.

Just out of curiosity you say this is going on a trailer? If you can have the support structure for the floor be part of the trailer than you can probably just have a perimeter of wood in the floor plus maybe one crossmember down the middle just for attachment points. The aluminum runners probably wouldn’t be necessary unless there is something I’m missing.


If yo look at the early photos of my build you will see that the foam under my floor just sits on the trailer cross members and is supported that way. Then there is a 15/32 plywood layer on top of it for crush protection so feet don’t cause dents. The plywood layer also gives me something somewhat substantial to bolt to. There is NO wood cross pieces or perimeter in the bottom layer and I could carefully walk on it.


What I’m saying is you could make the camper super light if you had the trailer doing the supporting.
With the mattress and some fiberglass holding the unit together all you need is something for the hold down bolts to grab. Probably 2x2s running along the inside corners of the long sides would suffice.
Tyrtill
Teardrop Advisor
 
Posts: 83
Images: 14
Joined: Tue Mar 19, 2019 4:36 pm
Top

Re: Foamie floor

Postby gregkn73 » Mon Jun 22, 2020 11:02 pm

Tyrtill wrote:162310

The red parts are cantilevered and would probably snap the foam without either a lot more glass or a little support.

I would recommend running the wood the other way to support this cantilever or put some foam runners parallel to the aluminum along the edges.

Just out of curiosity you say this is going on a trailer? If you can have the support structure for the floor be part of the trailer than you can probably just have a perimeter of wood in the floor plus maybe one crossmember down the middle just for attachment points. The aluminum runners probably wouldn’t be necessary unless there is something I’m missing.


If yo look at the early photos of my build you will see that the foam under my floor just sits on the trailer cross members and is supported that way. Then there is a 15/32 plywood layer on top of it for crush protection so feet don’t cause dents. The plywood layer also gives me something somewhat substantial to bolt to. There is NO wood cross pieces or perimeter in the bottom layer and I could carefully walk on it.


What I’m saying is you could make the camper super light if you had the trailer doing the supporting.
With the mattress and some fiberglass holding the unit together all you need is something for the hold down bolts to grab. Probably 2x2s running along the inside corners of the long sides would suffice.
Thanks again for your very helpful thoughts.

I would like to use the rtt onto my car alternatively to the trailer. When I am going to 2-3 days trips, mount it onto the car, during summer vacations, onto the trailer.

So I need the floor of rtt to be able to carry away the weight of people....

The aluminium rails are just for quick mounting- demounting. Look at the photo. My scetch would be more correct, if I have embedded them into the floor. I hope the photo clarify my plan. Is cantilevering still a problem? Thanks again.Image
Image
gregkn73
Teardrop Inspector
 
Posts: 19
Joined: Thu May 28, 2020 4:09 am
Top

Re: Foamie floor

Postby GPW » Tue Jun 23, 2020 4:05 am

I hate to throw a Skunk in the camper , but the Floor is Everything !!! It supports the whole cabin , and the people inside … JMHO, I prefer a stout floor and a Lightweight cabin … With a light PMF Foam cabin , we’re still waaaay lighter than the commercial units … ( last longer too) :thumbsup:
There’s no place like Foam !
User avatar
GPW
Gold Donating Member
 
Posts: 14911
Images: 546
Joined: Thu Feb 09, 2006 7:58 pm
Location: New Orleans
Top

Re: Foamie floor

Postby gregkn73 » Tue Jun 23, 2020 4:54 am

GPW wrote:I hate to throw a Skunk in the camper , but the Floor is Everything !!! It supports the whole cabin , and the people inside … JMHO, I prefer a stout floor and a Lightweight cabin … With a light PMF Foam cabin , we’re still waaaay lighter than the commercial units … ( last longer too)
You are absolutely right for tear drop trailers. But in my case, is a roof top tent. Rigid roof & floor, fabric sides. No cabin :-)



Image
gregkn73
Teardrop Inspector
 
Posts: 19
Joined: Thu May 28, 2020 4:09 am
Top

PreviousNext

Return to Foamies

Who is online

Users browsing this forum: No registered users and 9 guests