Method to raise a fiberglass high-top.

[Mobilesport]

If epoxy is your exclusive resin we probably dont need info on fiberglass , maybe we 
Should just use epoxy

 

[Konaexpress]

If epoxy will hold up to pounding waves, I think it will hold up to wind shear! The guys and gals that make foam teardrops in another forum drag those things behind them at 50 to 70 mph.

For my own comfort, I would add a thin skin on the front that is taking a beating but I think it would hold up nice in wind and rain. Just remember to paint it every so often.

John

 

[Konaexpress]

If epoxy is your exclusive resin we probably dont need info on fiberglass , maybe we 
Should just use epoxy

If I understand how this works, no you don't need it if the epoxy is put on a solid(ish) surface. The small, tight and strong fibers of fiberglass laid in different directions give it added strength. 

I'm wondering if you could make a sandwich core of very thin skin, foam, skin and epoxy? This should make a very tough shell.

 

[Konaexpress]

Instead of spraying foam could you very simply buy some of 
those foam rigid panels and cut down to the size and the angle you 
want and then tape it all together with that chrome looking hvac tape.
You would have your roof very quick and simply but it would'nt be structually sound so
you coat it with the marine grade epoxy , Would Marine grade epoxy make it strong enough to withstand high winds?

From what I understand, you don't need tape. Just glue the ends with gorilla glue.

 

[SternWake]

Cedar can be lightweight but it is neither super lightweight nor particularly strong.

The weights of my hollow cedar surfboards are basically double of a lightly glassed foam board, one which has two layers of 4 oz cloth on the deck and one on the hull, but my wood boards can last forever if maintained, whereas a foam boards life is limited as it will get too flexible and feel 'dead' under ones feet, if it does not break in half first.

Building a lightweight roof out of cedar and fiberglass and/or foam is NOT a project I would take on unless compensated with a highly ridiculous $$ figure, though I have all the skills and experience and tools to do so.

All resins need some type of composite underlayment, and this can vary from 0.5 oz per square yard and be super fine, to woven roving which is something crazy thick can weigh 24 oz per square yard, and cures to as thick as 18 gauge steel. To paint just a layer of epoxy( well several, keeping in mind secondary bonding issues) would make it waterproof, as long as it was applied to a cooling surface which would not blow bubbles through the curing epoxy. The adhesives in the reflective mylar or aluminum tape 'might' impede both the cure and the adhesive properties of the epoxy. Getting an even thickness coat of epoxy painted onto an uneven surface with no composite reenforcement is quite difficult.

Epoxy degrades quickly in UV light. It needs to be protected with paint or varnish, and varnish itself only lasts so long in direct sunlight.

Do not attempt to saturate fiberglass matting with epoxy resins. The matting needs the styrenes in polyester and vinylester resins to go clear. Fiberglass matting is the haphazard looking stuff with about 4 inch long fiberglass strands going in multiple directions and which is used in most fiberglass roof molds rolled out and saturated in place with various tools. Or the 'Chop gun' can be used to spray the gel coated mold for speedy production with more weight and waste. Fiberglass matting is more user friendly in that it can be stretched and compressed into and over molds easier than fiberglass cloth.

If one screw up fiberglassing something, the job instantly turns 3 times harder, as removing a poor job requires huge amounts of sanding, and if you have not sanded fiberglass and gotten the 'itch', well be happy for that. Properly prepping the resanded surface and reapplying it correctly makes a simple task infuriatingly frustrating anbd labor intensive. Mistakes cost a lot more than just time and labor, but material too, such as the sandpaper and dust masks and gloves and razor blades and mixing cups and waxpaper and mixing sticks and masking tape, in addition to of course the wasted resin and fiberglass .

New methods need to be tested. I would never plan on epoxy sticking or even perhaps bonding to mylar or aluminum tape without first testing it. In fact I would never even bother trying as there is no possibility of mechanical tooth on such a surface and the bond would have to be chemical and epoxy does not bond to some plastics.

My favorite Epoxy is from System3, My least favorite Epoxy is the most well known name brand, West SyStems. A cheap middle of the road epoxy can be gotten here:

http://www.fiberglasssource.com/sunshop/index.php?l=product_detail&p=88

This epoxy is prone to 'fisheyeing' when painted on a surface. Minor dust nubs or other surface contaminants repel the epoxy and these mini craters form. Never had that problem with System3 resins unless the contamination was horrid and visible to naked eye, like left over adhesive from masking tape.

The linked epoxy has a pot life of about 20 minutes. After mixing completely in the exctly correct ratios, One needs to either get it out of the cup ASAP on the work itself or spread it flat on another surface to reduce its condensed mass. Then one will have about 20 minutes with which to saturate the fiberglass with it before it thickens too much.

If a large batch is left in the mixing cup it will get smoking hot in about 5 minutes causing a cursing fit, and nearby objects to be launched into low earth orbit followed with a fury of curses.

 

[TMG51]

As far as working with fiberglass I am going to copy and paste something I wrote in another post:

Nevermind, I can't find the thread and I am certainly not typing it over

Had one too many to work the search feature tonight?

Working with fiberglass can be messy frustrating work for a newbie to the process.

'Fiberglass resin' as it is erroneously but commonly called, is actually polyester resin, and this can come in laminating and sanding versions. The sanding version has a wax like surfacing agent which rises through the resin after application and seals it which allows the resin to cure fully  underneath and then it can be sanded.

With laminating resin there is no surfacing agent the the resin will remain gummy until it is covered.  It will gum up sandpaper, it will not sand.

Polyester Finishing resin/Sanding resin can be made by mixing surfacing agent into laminating resin.  Finishing resin can be applied directly on laminating resin, but finishing resin must be sanded before anything will bond to it.  Laminating resin is used when secondary bonding of another layer of resin is to be applied after curing.  Sanding resins can be used in place of laminating resins but Must be sanded before any hope of secondary bonding can occur.  Sanding resin is not quite as strong and is slightly less flexible than laminating resin.  laminating resin will remain  porous if not covered with a layer of sanding resin, which also remains slightly porous on a microscopic level.

Polyester resins cure a bit less flexible than Epoxy resins, but they are more resistant to heat, and UV light, and are much less expensive.  The MEKP catalyst/hardener is really toxic stuff.  Methyl ethyl ketone peroxide bad ****.  the rate of cure can be controlled by the amount of MEKP added to the resin.  Too much MEKP can catch the resin on fire, and the fumes of polyester resin on fire are unpleasant and unhealthy in the extreme.

Polyester resins also do not bond nearly as well to wood as epoxy resins, and will not bond at all to some oily woods.  polyester resins will eat many types of foam.  A barrier coat needs to be applied to be able to use polyester resin on regular styrofoam and most types of insulative foam board.

Epoxy resins are much more expensive, and must be mixed exactly in the ratio prescribed, either by volume or weight.  Miss this ratio by more than 3% and the epoxy will not cure properly with is full strength properties.  Some epoxies have slow medium and fat hardeners.  Some epoxies can allow  these hardeners can be mixed to a specific cure time, others one must not mix the hardeners, but use the fast medium or Slow only.
Epoxy bonds much better to most all surfaces but for some plastics. compared to polyester resin.  
Epoxy is more flexible than polyester resins and will stretch more before breaking.  .
Epoxy will bond to and can be applied to polyester resins, but polyester resins 'might' not cure at all on top of a cured epoxy resin, and if it does cure it might not bond very well, relying solely on 'mechanical tooth'.( sandiing scratches)  Any dings/dents, and the polyester can shatter and peel from the epoxy below it.

Epoxy can be applied to most any foam without dissolving it.   Some brands and types of Epoxy can be stinky during curing, but some epoxies are quite mild in smell.  Polyester resins will have everyone in the neighborhood downwind aware you are working with polyester resins, and the smell lingers in hair and clothes and seeming one's nostrils too.

Epoxy hardener is also nasty stuff.  Some people can be hyper sensitive to epoxy hardeners, others can develop sensitivities over time. If one sands freshly hardened epoxy the dust is toxic, but fully cured epoxy the dust is inert, but fully cured epoxy is difficult to sand.
Tools used with polyester resins must use acetone to clean the tools afterwards.

Epoxy resins and one can clean the tools with distilled white vinegar as long as the epoxy has not cured. I prefer a mix of 91% rubbing alcohol and Distilled white vinegar for cleaning squeegees mixing stick/cups and gloves after application.

Acetone can be used with Epoxy for tool cleaning, but never never wipe uncured epoxy from your skin with acetone as this is an efficient toxic chemical delivery system directly to your bloodstream and a great way to develops an ugly sensitization to the amines in the hardener.

Epoxy degrades quickly in UV light, some more than others  Epoxy will yellow much quicker in direct sunlight if not protected with a paint or other UV light blocker.  Some Epoxy resins claim to have UV inhibitors built in, but these still do not last as well as polyester resins in direct sunlight.  Epoxy needs to be painted/varnished, and many epoxies will have an 'amine blush' form during curing, and more so when exposed to high moisture levels during curing.  This amine blush can be removed with water and a scotchbrite pad, and needs to be removed before painting, or adding another layer of epoxy.  There are some 'blush free' epoxies that do not have issues with secondary bonding, or at least that is what they claim.

So, consider the facts above when deciding to buy some fiberglass and some resin and going to town.  Removing a mistake is well  more than twice the work before the second try can even be attempted.

I have launched various fiberglass working tools into low earth orbit followed by  a stream of curses in the course of first learning to work with it.

Masking tape and clean cardboard all areas where you do not want resin, and clean cardboard itself can be used as a 'wet out table' where one wets out precut strips of fiberglass, squeegees out the excess resin, picks them up with gloved fingers and lays them in place carefully, overlapping in corners or bends trying to keep bubbles from getting trapped underneath.

The wet out table method  is much less frustrating than cutting fiberglass, placing it in the desired area dry, then trying to saturate it in place, but that method has its time and place too.
All fiberglass conversion van roofs are made with polyester resins.  The exteriors could be a gel coat like a boat, or painted like the rest of the vehicle.  the inside of the roof is likely laminating resin without a layer of a layer of sanding resin painted on as sanding is not required on the interior.

I recommend using polyester sanding resin for use on conversion van roofs unless one already owns epoxy, or one really requires epoxies superior chracteristics like superior bond strength and strength in general, but of course they need to be painted and not allowed to exceed ~170F.

The fiberglass resins sold in autoparts stores is usually dark brown, and if one has no choice but to apply these in direct sunlight then overheating and too fast a cure will result, along with more a more brittle finished product.  the best fiberglass resins are actually used on Surfboards, Silmar brand, but this is 2 to 3x as expensive compared to lesser polyester resins.

If you are in a area with Marina's nearby, try and get resin from them rather than from autoparts stores or from big box home stores.

Polyester resins also need to be tightly capped and kept cool.  They are always in the process of hardening, slowly, and as such have a limited shelf life.  The MEKP catalyst just speeds the process


Epoxy resins have a much longer shelf life, some say unlimited, but should be protected from freezing temperatures if possible.  The Epoxy resin itself might turn all white and cloudy and appear thick if exposed to cold conditions over a period of time, but submerging the bottle in warm, not hot water, and not over the cap, will turn milky cloudy epoxy resin clear again with enough time and warm water.

My favorite epoxies are System3, but they are quite expensive compared to some other epoxies.

If one has their heart set on Epoxy, but is also on a budget:

http://www.fiberglasssource.com/sunshop/index.php?l=product_detail&p=88

System3 is 50% more expensive for their general purpose epoxy, their specialized epoxies like clearcoat/ Sb112 are 100% more expensive.

My least favorite Epoxy is West Systems, but they have the best marketing team and are the most recognizable name.  They have strange mixing ratios like 4 parts resin to 1 part hardener or 5 to 1, which opens up more room for error in precise mixing.  they also have a lot of Amine blush and secondary bonding issues because of it.

Most other epoxies are a simple 2 to 1 ratio resin to hardener which is much harder to thuck up.

The Apex brand epoxy above is OK, and good to very good for the low price, bt in my experience it does not have the superior bond strength of System 3 epoxy, and it is more apt to form a visible amine blush in humid conditions.  Also when one is applying a final layer of Apex epoxy, and dust or surface contaminants cause the painted layer to be repelled and it leaves a mini crater or 'fisheye', which is unsightly, and a PITA to remedy, the easiest method of seeking perfection, is to sand the entire layer off and take extra precautions against dust and surface contamination for the next attempted application.

I was not even aware of the fish eye proclivities until I switched from System 3 epoxy resins to the cheaper Apex epoxy option.

There are another dozen brands of epoxies marketed toward the surfboard building market.  I've not tried them all.  these are generally made with a faster hardener to speed production, but then one has a shorter time to actually apply the resin.

One issue with both Epoxy AND polyester resins is they exotherm.  They create their own heat when mixed.  If left in a large mass like a mixing cup they will get super hot quite quickly and start to harden in the cup and start smoking and possibly catch fire.  This is worse with epoxy, especially the faster hardener versions.  The trick is to to get most of the epoxy out of the mixing cup as quickly as possible after a thorough mixing.
One other thing of paramount importance with Epoxy, is it must be thoroughly mixed,  the Mixing stick must be able to get into the corners of the mixing cup, as well as scrape the sides.   Do Not allow any Epoxy to escape the mixing cup when mixing, this will throw off the resin hardener ratio leading to an improper cure, the mixing stick itself must be scraped on the sides of the cup and then the whole cup mixed until one can no longer see any streaks in the epoxy.  This can seriously take 5 minutes of stirring even with a mixing stick perfectly matched to the mixing cup.

 

[debit.servus]

debit.servus ,,  Can you draw a picture of your idea? And post.
Thanks

I assume your talking about building a spacer.
It would'nt be aerodynamic would it?

The upper drawing is what I am talking about. A metal space going in between the bottom lip of the high-top and support ring on the van body. If one has metalwork skills, one can fashion a spacer ring to raise an existing fiberglass high-top for a 2 to low 3 digit sum. The same method is a low-cost way to turn a 4' tall truck camping setup into a stand-upright-inside living space, by raising the cover 4-6' up. Come to think of it one could build a truck camper using this method.

If one is cares about rig height, and has more advanced metalworking skills or $$$$, a mechanism could be fashioned/bought that raises and lowers the high-top.

 

[SternWake]

Had one too many to work the search feature tonight?

I checked two posts I thought it might have been typed within, then said eeF it.

Thanks for the cut and paste.

Not been drinking, I gots a belly to lose. ~ 10 Lbs this year so far.
 Seems to be the easiest way to lose weight, well that and breathing through my mouth when driving near an In'N'Out burger and that evil intoxicating aroma.

 

[Mattkcc]

Are you sure the Marine grade epoxy wont eat into the foam?
I was suprised to find out that fiberglass resin wont eat into foam ,.
Come to find out thats how they make surfboards , they fibreglass over a piece of foam. I hope yore right because marine grade epoxy sounds like it would be easier to work with then fiberglass.

No I've glassed foam on several project's, It's a very common use for epoxy. You can purchase a small amount and try it on foam. The only time I've had a problem with foam is trying to put paint directly on it.

 

[debit.servus]

I think if I was going to go to all of that trouble, I would prefer to build an all new hybrid foamie style top to my own specifications and aerodynamics.

Instead of spraying foam could you very simply buy some of 
those foam rigid panels and cut down to the size and the angle you 
want and then tape it all together with that chrome looking hvac tape.
You would have your roof very quick and simply but it would'nt be structually sound so
you coat it with the marine grade epoxy , Would Marine grade epoxy make it strong enough to withstand high winds?

High-top built from foam block, kept together with hvac tape and coated marine grade epoxy? This needs to be built and tested! Could become a low cost option to hightop a van and insulate at the same time!

If epoxy will hold up to pounding waves, I think it will hold up to wind shear! The guys and gals that make foam teardrops in another forum drag those things behind them at 50 to 70 mph.

For my own comfort, I would add a thin skin on the front that is taking a beating but I think it would hold up nice in wind and rain. Just remember to paint it every so often.

John

Foam block high-top? As above, this needs to be built & tested!

...
I'm wondering if you could make a sandwich core of very thin skin, foam, skin and epoxy? This should make a very tough shell.

Wondering too...

Another thing one can devise for a DIY hightop is build it out of wood (for those without metalworking skills) or out of plate metal. One could mod their van to look sprinter-like this way.

Of course there are those people who obsess about every little thing that hurts fuel economy, and because of that (or not having a desire to live in a high-top van) their rig is regular-top.

Here is a great way to improve ones van fuel economy at least 25%: Remove the windshield and back windows (if one has them, if not remove the back doors) to reduce drag and save fuel! I reccommend this for you Off Grid 24/7, reduce frontal surface area 50% on a reg top van! Just wear safety goggles and a windbreaker whenever on the freeway!

 

[TMG51]

Of course there are those people who obsess about every little thing that hurts fuel economy, and because of that (or not having a desire to live in a high-top van) their rig is regular-top.

Here is a great way to improve ones van fuel economy at least 25%: Remove the windshield and back windows (if one has them, if not remove the back doors) to reduce drag and save fuel! I reccommend this for you Off Grid 24/7, reduce frontal surface area 50% on a reg top van! Just wear safety goggles and a windbreaker whenever on the freeway!

I'm pretty sure you're joking with that last, but you make it hard to tell. Incidentally though I don't think removing glass would improve aerodynamics (economy) at all. As for these obsessive people, do you know of any other than yourself?

 

[Konaexpress]

Hahaha! Just found a thread in another forum where a guy made a truck camper out of foam! So yes it will hold up to travel on the road. Looks like he used the poor mans fiberglass method, like how they used to make boats before fiberglass.

John

 

[debit.servus]

I'm pretty sure you're joking with that last, but you make it hard to tell. Incidentally though I don't think removing glass would improve aerodynamics (economy) at all. As for these obsessive people, do you know of any other than yourself?

Imagined that fuel saving trick for a long time, and decided to share it here. Think about the science, removing the windshield and back windows will reduce frontal wind surface area; which in turn reduces drag; improving MPG. I don't personally know any cheapskates, depravationists or extreme ecomodder; there are some here however, and it's their life not mine (If you're happy without A/C or a stand-up-inside rig you have my full support, forcing oneself to be happy without is another thing).

We're getting off topic here, lets get back on topic which are creative and low-cost ways to raise a fiberglass high-top.

 

[WheelEstate USA]

Just a side note...most States require a windshield.

 

[highdesertranger]

an A-frame hoist would be my choice. but I realize not everybody has access to an A-frame. a tall oak tree would work, but alas where to find a oak tree. so I would build me some saw horses. some tall saw horses. this would take some engineering to get the high top up on the saw horses, but I feel it could be done fairly easily. I assemble my A-frame on the ground and raise it all the time. then when you are done you could cut the saw horses up for firewood. that is if you have any use for firewood. for that matter you could build an A-frame out of wood and then you would have even more firewood. highdesertranger

 

[SoulRaven]

Here is a great way to improve ones van fuel economy at least 25%: Remove the windshield and back windows (if one has them, if not remove the back doors) to reduce drag and save fuel! I reccommend this for you Off Grid 24/7, reduce frontal surface area 50% on a reg top van! Just wear safety goggles and a windbreaker whenever on the freeway!

Thanks, but I'm perfectly happy with 15-18mpg and having everything rain & wind proof...

 

[TMG51]

A van is probably more aerodynamic WITH the windshield and doors. Frontal area is just one factor affecting drag coefficient.

Guy

^this