New Hightop Option

[calsurf]

Looks great, congrats. I wish there was a "Like" button for each post on this forum

[jimf909]

^^^ <Like>

Agreed.
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- Jim

[dobryan]

[J Charlton]

When fibreglass cures there is a thin layer of wax that is released to the surface of the wet resin/hardener mix - this is deliberate to limit the contact with the air and slow the curing rate of the mix. The first step of any install is to put several pails of warm soapy water into the inverted top and give the inside a thorough scrub, wash and rinse. nothing will bond well with the fibreglass if this is not done - the waxy surface residue has to be removed.
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NAHT hightop availability May 18 2023 -
Bend Oregon - for Oregon, California- (7 tot , 3 available), Kennewick Wa (6 tot, 1 available), Small Car Performance Fife Wa. (7 tot 4 avail ), Fairbanks Alaska (1 tot 0 avail)
Future availability TBD : Springfield Mass. Staunton Va, Florida, Colorado, Grand Junction Co., SLC probably late 2024

[DuncanS]

[dobryan]

Fiberglass itself does not cure. The adhesive, in this case epoxy, is what cures.

As Duncan said try the test again but really sand off that shiny surface layer from the epoxy.

I used an angle grinder on my euroBus top and have no doubt it is bonded.

That being said I will use 3M5200 on my next one for the ease of working time. As Duncan said you must wait many days for it to cure.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[tim_ha]

Here are results from a Sikaflex 221 metal to fiberglass bond test.

I did the exact same surface prep as I did for the Evercoat Maxim. According to the tech sheet, this ~3mm thick application cures in ~2 days. I gave it 3. I am not convinced it was fully cured because I smelled it as soon as the failure occurred (and quickly put on my ventilator). Note that the Sikaflex had no problem bonding to the same surface prep. As can be seen in the video, I was pulling on it hard enough to nearly damage the fiberglass. The failure was as I pulled on the edge so that there was only stress along the edge of the bond. This type of stress would be impossible on a hightop. Also, look at how much the ~3mm thick bond is able to flex! I wouldn't hesitate to use this adhesive.

Failure testing:

Link


Comparing the data sheet for the Sikaflex 221 to 3M 5200...
Sika has tensile strength of 1.8 MPa = 261 psi
3m 5200 overlap sheer strength is reported to be 530 lb/in2 for cold rolled steel and 360 lb/in2 for Fiber-Reinforced Plastic.
I am not sure if this is an apples to apples comparison.

I also set up another test of the Evercoat Maxim with suggested improved surface prep. I will post results when I have them.

Based on testing thus far, I am considering breaking the Evercoat Maxim bond and cleaning all of it off of the fiberglass and as much off of the metal as is reasonable. Then I can improve my surface prep of the fiberglass and use either Sikaflex 221 or the 3M 5200 Fast Cure that I have on hand to completely redo the bond.
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1986 Syncro Sunroof EJ22
www.subagonsouth.com

[DuncanS]

https://multimedia.3m.com/mws/media/576967O/3mtm-marine-adhesive-sealant-fast-cure-5200.pdf
https://technicaldatasheets.3m.com/en_US?pif=000890

These are the data sheets for both 5200 and 4200. 4200 is not as strong but is removable--with difficulty--unlike 5200 which can not be removed. Check the data sheets, for 4200, it has a psi of 125 on steel and 20 on fiberglass. 5200 is much stronger with its bond. If you remove it from fiberglass, it will tear apart the laminations at it is stronger than the fiberglass resins. I found this out the hard way on my boat. It is NOT a bedding compound, it is a bonding agent.

Although they don't mention it, 5200 comes in three colors--white, black and mahogany.

I didn't check it out, but assume slow cure is stronger. That may not be correct.

Duncan

[DuncanS]

[tim_ha]

[dobryan]

Yep. I would not debond what you have done. Add 5200 to it and I think you'll be fine. (It is what I would do if this was mine.) YMMV.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[J Charlton]

It would appear that the 5200 is now a better choice than the Evercoat for bonding the top to a van. The selection of the Maxim, and subsequent substitution of other panel adhesives by some installers was based on the research at the time when we began installing hightops. Things change, new products emerge and best practice follows.
I should mention - perhaps as a disclaimer - that all of the advice that I have given folks wrt installing a hightop has been specifically and solely intended for a NAHT hightop. The NAHT is designed to maximize the contact patch between hightop and van along each side - if another hightop does not have the same mating surface contact patch then other installation protocols would have to be developed specifically for that top. Similarly, the NAHT top is constructed of hand laid fibreglass - we know of its characteristics and what has been successful wrt preparation of the contact patch and bonding - what we know re the NAHT top may not apply to a chopper gunned top.
I mention this because a few years ago someone brought 10 hightops into the west coast from Europe - that they sat in San Diego while folks who had been part of the group purchase called our installers asking when they were going to get them (we had Nothing to do with anything related to tops) and questions wrt to installing them - this was all annoying enough - BUT the final straw for me was a call from a lawyer representing someone who had installed one of the 10 imported tops and had it blow off - insinuating that I was somehow culpable because the person had "followed all of the recommended steps as per the website and on the "New Hightop Option" Samba thread. I pointed out that the discussions to which I contributed were specifically related to the NAHT tops and not intended to be a generic installation guide. It turned out that the top that blew off was designed to be secured to a flange that went around the entire interior perimeter of the van, riveted to the van itself and the hightop then fastened to the flange - the top itself "sat" above the contact patch that we use for NAHT installation. None of this information was available from the person who imported the tops - in my opinion, it should have been.
If I am asked for advice wrt the installation of a top other than a NAHT I usually try to be as helpful as I can be but always recommend that the person contact whomever they bought the top from for their specific advice and guidance. I would have done so wrt Tim_Ha as well had I realized that we were talking about a top other than a NAHT. I'm "all for" the availability of a variety of hightops but I think there's a degree of unfairness if the folks supplying tops other than the NAHT do not actively support the installation of the tops they are supplying and rely pretty solely on the collective experience and body of knowledge resultant from NAHT installs.
The current discussion wrt to adhesives is an example - many - if not all - of the people who have contributed to the discussion with respect to the installation of the top in question have responded from the perspective of their experience in installing a NAHT top - that experience may or may not be appropriate or relevant to a different shaped hightop that may be constructed differently and may contact the van differently than the NAHT. It's the nature of most of us and this forum to be helpful and supportive whenever we can be and so we respond whenever we can with the best advice we can offer. Having said that however, I firmly believe that the first source of advice and support should be provided by the supplier of the product.
JC
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NAHT hightop availability May 18 2023 -
Bend Oregon - for Oregon, California- (7 tot , 3 available), Kennewick Wa (6 tot, 1 available), Small Car Performance Fife Wa. (7 tot 4 avail ), Fairbanks Alaska (1 tot 0 avail)
Future availability TBD : Springfield Mass. Staunton Va, Florida, Colorado, Grand Junction Co., SLC probably late 2024

[tjet]

Hi Tim, glad you made a test sample.

If the humidity is too low, it will take much longer for it to cure (maybe 4 to 5x longer). Ideally, it needs to be what the epoxy calls out for. It will still cure though. Temp is important too, but I think humidity is more critical.

[tim_ha]

[J Charlton]

tim_ha - let me apologize if what I wrote was taken as a "shot" at you personally. It was not intended to be. My only intention was to raise the awareness of the T3 community wrt providing generic advice without referencing the specific circumstances that provide the basis of one's experience, hence the advice. My example of the "contact patch" variance between between hightop shapes illustrates the point.
I welcome your experimentation and the results you achieved with the alternative adhesive - I'm sure it will become the "go to" of future NAHT installs. However - and perhaps I'm being overly cautious - I will continue to be wary of recommending any adhesive or protocol for the adhesion of a hightop to a T3 other than a NAHT top, simply because without seeing the top and how it fits I would not know how extensive the "contact patch" between the van and hightop is. I emphatically believe that the recommendations for attaching any hightop should come from the producer / fabricator of the specific top so that they can "stand behind" their product and be held accountable for its performance.
Thank you for your research and your input.
JC
_________________
NAHT hightop availability May 18 2023 -
Bend Oregon - for Oregon, California- (7 tot , 3 available), Kennewick Wa (6 tot, 1 available), Small Car Performance Fife Wa. (7 tot 4 avail ), Fairbanks Alaska (1 tot 0 avail)
Future availability TBD : Springfield Mass. Staunton Va, Florida, Colorado, Grand Junction Co., SLC probably late 2024

[DuncanS]

[J Charlton]

Thank You Duncan !!
_________________
NAHT hightop availability May 18 2023 -
Bend Oregon - for Oregon, California- (7 tot , 3 available), Kennewick Wa (6 tot, 1 available), Small Car Performance Fife Wa. (7 tot 4 avail ), Fairbanks Alaska (1 tot 0 avail)
Future availability TBD : Springfield Mass. Staunton Va, Florida, Colorado, Grand Junction Co., SLC probably late 2024

[tim_ha]

[J Charlton]

Just an update for folks who are considering the addition of an NAHT top to their van. The current "availability" figures posted in my sig line are - or can be somewhat misleading - I'm currently in conversations with folks which, if all culminated in purchases of tops, would reduce the current inventory of tops significantly. In some locations, existing inventory would be eliminated. The slowdown of the economy of North America has had an impact on discretionary spending and the impact has been specifically more noticeable in the budget conscious DIY sector. I mention this just as a "heads up" - I suggest monitoring top availability as per my sig line and using your best judgement if you are hoping to either install a hightop yourself or have one installed for you.
The one exception to this would be installations done by our fabricator/ installer Terry in Lakefield, Ontario, Canada. Terry can almost always make up one or two or three tops for installs that he would do at his shop in Lakefield. Anyone East of the Mississippi who would be considering having a top installed would be well advised to consider either shipping their van to Terry or driving and flying back and forth to have a top installed. Given the current exchange rates CDN dollar relative to USD the savings in cost of labour could make it attractive. The cost of the top would be the same in USD however. Terry likes to do two installs pretty much simultaneously and he has a "time window" opening in the next 4-6 weeks. Contact me for further details if interested.
JC
_________________
NAHT hightop availability May 18 2023 -
Bend Oregon - for Oregon, California- (7 tot , 3 available), Kennewick Wa (6 tot, 1 available), Small Car Performance Fife Wa. (7 tot 4 avail ), Fairbanks Alaska (1 tot 0 avail)
Future availability TBD : Springfield Mass. Staunton Va, Florida, Colorado, Grand Junction Co., SLC probably late 2024

[syncrodoka]

There was a post that coast mountain high tops are going to be made in the US. Vivid vans in BC and santa cruz will be an authorized dealer, will install as well.