Topic: Making Cafe Seat help.

[zeus87]

Alright, i want to make my own cafe seat but need some information. ( i searched everywhere)

I want to make a mold out of foam:  Where do i get the foam? (i know fiberglass eats through styrofoam), and how do i lay fiberglass on top of it so i can remove the foam after the glass is done drying? (maybe wax paper or something?)  Thanks- Justin

[Jinxracing]

I did a quick search on Google and came up with a couple of links:

http://www.britbike.com/ubb/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=58;t=000437;p=1
http://rawge.bravepages.com/minichoppers/seat/seat.htm

Then did a quick search on the forum here and came up with these links:

http://forums.sohc4.net/index.php?topic=15920.0
http://forums.sohc4.net/index.php?topic=19897.0
http://forums.sohc4.net/index.php?topic=33129.0

Where exactly were you searching?

[merc2dogs]

  If you use the yellow poly iso type foam mostly sold as insulation sheeting, the resin doesn't attack it.
 Most spray foams are also resistant.
 
 Painting the foam with a latex house paint is also enough to protect it from the resin.

 If you use epoxy resin for the fiberglass it is 'safe' for most types of plastic or foam, and doesn't need any speacial precautions as far as air quality, quite a bit safer in confined areas than the regular resin.  Much stronger also.

  My preffered method is to rough it out with foam, apply a light coat of plaster, then work the details into the plaster. spray down with latex paint or varnish and wax up with johnsons paste wax so the layup or mold I'm making will slip off. But then I make quite a few parts that need a mold and not just a plug.

 If you want to use the foam as a structural element for stiffness, think about using a small plastic or metal box or maybe a jug as a filler, that way you'll also be able to use it as storage for papers and tools etc.

Ken.

[zeus87]

im looking to replicate the bubble cafe seats that are commonly seen.  I want to make it out of foam, then lay fiberglass over the foam.  When the fiberglass is hardened i would like to remove it and have the cafe style shell.  Thanks- Justin

[scunny]

the expandable foam I used is resin proof
acetone is widely used to dissolve the foam

[paulages]

the expandable foam I used is resin proof
acetone is widely used to dissolve the foam

i've never found an expandable foam that acetone or any other solvent will dissolve. they are definitely resin-proof though.

zeus- if you go the foam route, make sure you buy a sandable foam. here's a thread i started forever ago showing how i did mine-- there are plenty better versions out there, but here's one more anyway:

http://forums.sohc4.net/index.php?topic=7362.0

[fuzzybutt]

use the blue foamboard insulation like they sell at lowes and other home improvement stores. we use it here at home to model mountains and other landscape features for model railroading.you can get it from 1/4" thick up to 3 or 4 inches.

[paulages]

use the blue foamboard insulation like they sell at lowes and other home improvement stores. we use it here at home to model mountains and other landscape features for model railroading.you can get it from 1/4" thick up to 3 or 4 inches.

my only complaint with that stuff is that it is much harder to form your seat around the frame if you're going for a nice fit. it is easy to work with otherwise, for sure.

[swan]

I use ethafoam as a medium for making plugs and wrap it in duct tape or blue masking tape. Ethafoam is a closed cell foam commonly used for packing materials, kayak seats and padding, sports mats etc (free for me from my job) It sands reasonably well but I like the aforementioned idea of using plaster as a sandable layer over the top. Resin and glass do not stick to the tapes if you remove soon after it has set. You could wax it or possibly use a spray cooking oil (Pam)?

Check out the tanks and seats section on www.dotheton.com for all kinds of cafe seats (good and bad).

Pics of my method (kitty approved)

[zeus87]

now when you say expandable do you mean like "GREAT STUFF"?  I definetly like the foam that is shown in the picture, and i would like to just buy some from home depot (the blue foam) but fiberglass resin eats right through it...where can i get foam that wont be killed from resin?  Also i just wanted to use the foam as a mold, i want to keep the seat hallow for battery compartment use.  Now are you forming your seats as pictured, putting what on it so the resin wont eat through? then letting the resin/fiberglass dry and then removing the shell from the mold?  sorry to ask so many questions, i havent had much luck with fiberglassing.  Thanks!!

[paulages]

now when you say expandable do you mean like "GREAT STUFF"?  I definetly like the foam that is shown in the picture, and i would like to just buy some from home depot (the blue foam) but fiberglass resin eats right through it...where can i get foam that wont be killed from resin?  Also i just wanted to use the foam as a mold, i want to keep the seat hallow for battery compartment use.  Now are you forming your seats as pictured, putting what on it so the resin wont eat through? then letting the resin/fiberglass dry and then removing the shell from the mold?  sorry to ask so many questions, i havent had much luck with fiberglassing.  Thanks!!

yo zeus... check out the links, already.

[swan]

Avoid "Great Stuff" It ALWAYS makes a mess, gets all over your hands, clothes, carpets, etc., smells and takes long to set up, has air pockets and does not sand well.I found blocks of foam glued together, cut with serrated knife, sanded with a surfoam and sandpaper work well for me.

[zeus87]

good deal, thanks for all the info!

[troppo]

G`day justin
I`m doing the same thing at the moment. Use any foam you can get, even polystyrene, use PVA glue to glue layers together to get a block big enough for your seat. While thats drying go to your local discount shop and get a hand saw (the type used to cut wood) and a wire brush, real cheap tools are fine for foam and they will last ages if its all you use them for.
The saw will make easy work of roughing your shape and then use the wire brush to finese it 9it works really well believe it or not), once you have your foam block to the shape you want, mix up a good big bowl of 50/50 PVA and water then grab a 2 inch brush and paint 2 or 3 coats onto your foam seat, let this dry overnight at least and then set to with the fibreglass.
Once your glass has set up properly up-end it and pour in some petrol/ thinners/ acetone and swish around to disolve the foam, step back and admire your brand new one off custom cafe seat.
Now the hard part begins, you get to bog it to get the surface smooth.
A bit of work but well worth it when you stand back and think " I made that from scratch ".
Cheers mate
Troppo

[freezingprocess]

Hey Justin- Just wanted to throw my two cents at you. I made my own cafe tail section this winter. I actually used taxidermy foam and it worked really well. This is what I got: http://www.vandykestaxidermy.com/product/01330896/

I got an over-sized piece just to really make sure I had enough, and I didn't have to glue anything together. During my research I had read that sometimes the glue was harder to file/sand through than the foam making it difficult to work and get smooth results. This stuff was very easy to work with. It's dense enough that it doesn't compress easily (like if you push your finger into it), but it sands quickly, so you have to work slowly and cautiously.

I tried mold release on it, but the foam just absorbed it, so I went ahead without it and just scraped the foam out after the glass dried.

I wish I had taken more pictures during the process, sorry. I do have finished pictures though. Check out my flickr page- I have a bunch of pictures of the seat before I put any filler on it.
http://www.flickr.com/photos/14429764@N03/sets/72157602235789797/

[zeus87]

troppo:  So its as easy as buying the cheap foam from home depot, glueing it together with Elmers glue (just plain glue) then mixing the elmers 50/50 and painting the surface with a couple coats? this will stop the fiberglass resin from eatnig through the foam?  If so lay the glass on top of the glue painted foam, wait unitll it hardens than sand smooth?  Sounds to good to be true, let me know... Thanks everyone!

[tx750]

Here is one I found that looks pretty good.  matteofogione.com

[troppo]

G`day zeus
Yeah thats about all it takes, make sure you put several coats on the foam first, make sure you coat an inch or so of the underside of the foam in case theres any resin that creeps round the edge, you know how PVA or elmers glue as you call it dries like a plastic skin, it will protect the foam from the resin and when you have poured in the petrol and disolved the foam it should just peel off (i say should because i never bothered peeling it off lol)....
Got my tail coated in PVA tonight, gonna lay up the first layer or tow of glass tomorrow, seat base is already done so may be looking at a rough seat tomorrow afternoon.
Good luck with your build mate, hope it turns out the way you want.
Cheers mate
Troppo

[Ecosse]

swan, just so you know; your Cat on a Cafe is my new desktop image. Cool bike, cool cat.

[zeus87]

good stuff, if you snap a couple shots, i would be interested in seeing your progress.  Thanks!

[troppo]

I tend to get carried away when i`m doing things in the shed and forget to take pictures all the time, but i got a couple of snaps of this.... I layed up the  combing tonight so i`ll go out tomorrow andd get an extra couple of shots and post them.
Just remember to make sure when you put the pva on the foam that you dont dilute it any fiurthe than 50/50 and you put a few thick coats on it, i thinned it a bit far and wound up with a little shrinkage in the foam because the mix ran off and was too thin in places, nothing serious though.
I`ll have to try to take the camera out with me, the few shots i have and the couple i`ll get tomorrow should be of some use to you.
Cheers
Troppo

[KeithB]

Kudos for trying to make your own seat!
But if you don't get the results you want, here is a site with a great solution.
http://www.motobody.com/hondaz/CB750SOHC1969-77.htm#price

[zeus87]

good deal thanks! yeah im still thinking about airtech...i figure a little glass work would be good to have under the belt. 
P.S. its so wierd to me that elmers glue stays on the surface of styrofoam, i would think it would absorb it.  Thanks

[troppo]

good deal thanks! yeah im still thinking about airtech...i figure a little glass work would be good to have under the belt. 
P.S. its so wierd to me that elmers glue stays on the surface of styrofoam, i would think it would absorb it.  Thanks

It will stick, just dont mix it too thin and the styrofoam wont absorb at at all.
I didnt get out to the shed today as SWMBO`s brother and neice left to go back to england so i had a few beers with him and we kinda got carried away lol.
Anyway heres a couple of pics i took the first night i started on the seat to give you a starter, i`ll post a few more tomorrow (no drunken inlaws to distract me lol)


this is my second spare seat pan, notice the screws? they hold the seat together with bits of vinyl lol


this is the initial layup over the top of the old seat pan (i wanted to keep the box under the  seat as its handy)


roughly trimmed up with  hinge and seat lock fitted


and open


the foam blocks roughly placed to start thinking of shape for the cowl


when i post the next pics it will have skipped a couple of steps (i got carried away and forgot, OK? lol)
Cheers mate
Troppo

[troppo]

Got a little bit done today, so heres a few pics, like i said in my last post i tend to get carried away and missed a few steps in the pics lol.

heres the seat all layed up and cured, i`ve marked my rough trim line across the bottom if you can see it


I trimmed it up before i got rid of the foam as theres only one layer of glass and the foam added a lot of rigidity to it while i cut it, i poured some acetone into the coaming after i trimmed it and the sludge in the tin is all that is left.


Heres the seat on the bike mounted on the hinge and seat lock, I initially wanted to keep the under seat storage box on the mudguard but it just wont happen


This is the LED taillight i want to use, its actually a truck item but i thought it might work


I want to be seen but this might be a bit too big lol


So i had a little think and may go with the original grab bar and tail-light, had a play in paint shop, this is what i came up with. I`ll cut the tail-light mount off the grab bar and rotate it so its back to level and giving greater tyre clearance. Your thoughts would be appreciated.



Cheers guys
Troppo