yeah I blew that jpeg up 1000% to study it and funny thing is if it’s a hotcoat…
How come you don’t get any of those pockmarks we’re getting using Greg’s RR Bert?
I’ve never seen a open air (remember there’s fins here ) hotcoat of epoxy be that shiney and not have some pock marks or dimples prioir ro finishing… Almost looks like poly pour to me…
Only Bert knows
I know we in the bozo brigade are all envious to get that good of a glass like finish with our hotcoats…
I laughed when I saw that you blew the picture up to 1000%, I went to 400% 
I think the picture looses too much resolution when the file size is reduced. I think that Bert still has some (although much less) of the bump problems we are encountering. He mentions scraping resin of his wetout table to hit problem bubbles.
i have developed my own additive , i know it has similarities to gregs additive , i know we share some of the same ingriedients …
its probably the one thing that makes epoxy so easy to deal with …
a few times over the years i thought i almost had it , but didnt quite get there , it would react badly under some extreme condition , but this one works in extreme heat and cold , i can get away with dirt and grime , tape residue and it still flows and settles great …
when i told greg the ingredients , he confirmed that they were the ones , less a few more that he uses …
im happy with this one , even tho i do lose some strength , but im not fussed there because its a sanding coat , most of it comes off , its only there to fill imperfections in my vac-lam …
im almost there with getting a full gloss out the bag …
but getting tiny glitches in the weave …
so im hoping gregs more specific infusion resin will help …
i could just leave them there , but im looking for that fine crafted furniture look , where the wood has depth and everything is beautifully clear , even tho there is multiple layers of cloth …i know crew were happy with them years ago , but you have to just keep improving the system , well i do anyway …
hey benny as simple as it is …
laps really effect flex …
because the rail is the most dynamic part of the board , all the loads and movement converge there , its a fine line between locking it all up and like a standard urethane , not having enough to make it alive and twangy …
regards
BERT
Bert aint going to show us too much, even though we seem to be gettin close. Are those tapes 0-90 or ±45? I suggested in the technique thread that I recon he stacks up his skins say 10 boards worth at a time glass/balsa/glass /release /glass/ balsa/glass etc and infuses the whole lot, only the bottom skin has to be cut accurately, and then only if it is attached at the same time as the rails. I know that thae glass on the rails affects the stiffness of the board through experience, I had to repair the rails of my first board where they split in front of the finboxes (only 6oz on rails), and put a staggered 3 x4oz over as a repair, can really feel the difference.
I will hopefully be lamming my latest board next week if the deck goes on ok, and will be careful not to have too much of an overlap on the rail.
I think that Bert glasses his fins on with poly, hence the hotcoat first, sand the fin area and then glass on fins.
That pink must be tape, otherwise some of those boards have some very thick tails!!!
na no way , fins are structural , if i do use polyester , its only for gloss and polish , havent used it for a few years tho …
but have done a few recently with U V gloss , because the set up i was working in didnt have adequate spray facilities yet …
those boards in the pic are the very last ones to come off the west oz production …
regards
BERT
I got hit with a major dose of insomnia last night and I came up with my newest quess on the Bert Technique. Here goes:
Prefab the skins using glass on the outside of the wood only (this is the point were you can place a lot of your reenforcing glass (like mini deck patches)). This can be done with high heat and temperature.
Put the bottom skin on the board using a rocker table. Here’s my wild guess - This is the time to apply the HOTCOAT to the bottom of the board. My reasoning is to draw the resin into the voids when it is under vacuum. This would allow you to get away with way less of a hoatcoat and almost no sanding.
Use you template to cut out the shap of the board. I really like the idea of a router with a long bit and bearing so that you get a nice clean edge.
Apply the balsa rails with tape. Since they will expland past the bottom of the board you can true them up with a hand plane and sander (don’t want to hit the bottom skin too much). You can also put on the bottom rail roll an this point.
Shape the top of the board and put in a horizontal stringer.
Now its time to apply the top skin. The first thing that would need to happen is that the edges of the balsa would need to be thinned so that that lie nicely when they rap over the rails. Next you need to seal (My guess is epoxy and cabosil) the blank in the place were you dont want the resin to soak in. I bet that he leaves tiny foot spaces unsealed so that the resin would saturate the eps. I knew that Bert infuses his skins, but I was never sure what the advantage was since you can get a 1:1 ratio with hand layup. Last night it came to me : It would create negative pressure inside the balsa and draw anything that is on the outside toward the inside so … if you hoat coat at this point the resin will get drawn into the remaining voids in the glass and balsa and fill them up. I know that it sounds crazy to hotcoat at this point but helps to explain what I noticed about his rails. I had mentioned that there were gaps between the balsa, but what I didn’t mention is how perfectly the were filled with resin as if the resin what held in place by something (like maybe a vacuum bag) . The last part of the process is to allow a little air to enter the line so the the front section of the board gets bubbly epoxy. In order to do any of the infusion techniques requires you to invent Bert’s magic material (and I bet Bert doesn’t give any tips with this one since its one of his eleven secret herbs and spices). I think that you could get decent luck with with a hand layup but you wouldn’t be able to induce air to create bubbles.
Now comes the rail tape. I think that one of the reasons he has so many different rolls is because the rails do not get just one layer. I don’t know if you remember the picture of Bert standing on his board and somebody commented that the board flattened out more at one end than the other. I now think that is because of the differing amounts of rail tape that he used. This is one of the ways that he fine tunes the flex to the
How does this sound?
doesn’t your head hurt now?..
doors and hallways are played…
…anyone else interested in forks?
Yes and I also think I could use a nap!
After reading your post I was a little confused. Are you saying that the outer glass is saturated to a 1:1 or 6:4 and the inner glass only gets what is sucked through the outer layer gaps? My brain can’t wrap itself around a technique to get resin to flow through the layer between the foam and the skins. Does not wraping the rails allow it to flow in from all sides? How do you think this is done? I am very curious.
I wrote this post a few days ago and was not sure if a summary of what I thought Bert was doing was appropriate. After seeing where this post has gone I feel more comfortable sending it into cyberspace.
I agree JJP
Not Having any practical experience regarding this technique I can only give an educated guess as to what Bert is doing after reading most of his posts.
Here goes
Pre Vac balsa skins with top and bottom epoxy lams individually under High pressure along with heat to form a very flexible and strong top and bottom skin.
Vac Balsa rails on to shaped 3/4lbs eps
Take your pre vac/lammed skins and attach to top and bottom of eps with an epoxy/filler slurry.
Lightly coat skin and eps with slurry and place a pre cut piece of fiberglass between the two to act as a breather to spread epoxy between skin and eps.
Then pull vac on skins over eps.
Sand any place the skins overlap the rails on top and bottom to keep skins independent of rails
Use fiberglass tape with epoxy(as shown above) on the rails to strengthen the small gaps between the balsa rails and the skins.
Sand and Feather rail Glass
Hotcoat
This allows the top and bottom to be connected by only one layer of fiberglass, possibly allowing for more flex.
Keep in mind this is only my 3rd post and I have yet to pull 1hg of vac.
Starting my first board next week with help and encouragement from Daddio and Terry Price over at Cerritos college.
Wish me luck
Christian
Keeping in mind Gregs post in ‘Understanding Berts technique’ “Low tech is high tech”
Using an electric blanket to heat while keeping the epoxy to fiber ratio low is key.
I forgot to mention sealing the blank with spackle
Bert basically confirmed the rail glass can be used to adjust flex.
thanks Swaylocks and Bert for keeping the wheels spinning.
Remember to keep everything in your life in order
FAMILY
Surf
work
swaylocks
I’m bringing this thread back to life because I just finished my version of the rocker table. Its made so that when I’m not using it I can break it down into seperate rails and hang it on the wall. I think that I’m really going to like it. I was able to use aps3000 and take rocker measurements every 6 inches and quickly dial it into the table. I working on a way to shape the eps that will make the rocker table a real time saver.
That looks perfect. If I may, what is the material used as the surface? Total length?
But, DanB, is that surface glued or fixed to the parallel pieces of wood??? Or is it just lying over them??
Looking good, I like the idea for taking it apart.
Cool stuff.
Nice one Dan, keep us informed!! I am still going to make one when I have time, looks really neat and simple, I hope you are going to cover that mdf board with formica or similar (looks like 6mm?) Your pump will some how suck air through 6mm mdf and you cannot pull more than a couple of inches, believe me, I have been there!!!
I’m really happy with how its turning out. The more I surf my small boards the more I realize that I’m a longboarder so I made the rocker table big also. It is 10 feet long by 31 inches wide. It come apart really easy (probably 4-5 total setup time). Currently the top is only laying on the slats but intend to glue them down this weekend. I used varying sizes of eyebolts so that there would be more room for lateral movement on the ends where theres the greatest range on movement. Markyv, your correct that the top is around 6 mil (1/8th inch) mdf but it is melamine covered. Do you think that this would be okay? I looked at the 1/4 inch but it was really stiff. It seemed that it would make it very difficult to do things like tails kicks. I bet if I varnished the bottom of sheet it would help to reduce air from being pulled through.
Nice, Dan! I wouldn’t glue the flat to the slats, though. If you change the rocker, it won’t come along. Picture the rocker curve between any 2 bolts as the hypotenuse of a triangle. If you change the height of leg A - increasing or reducing height to alter rocker, the hypotenuse length also must change. But if it’s glued to the two slats at the two acute angles of the triangle, it can’t change.
If you varnish the bottom, you can probably add a couple suction cups to your vac pump setup and hold the sheet onto the slats with the same vac pressure you’re using in your bag.
Using the eye bolts gives the piece a lot of play and it lets the slats rotate. I’ve been moving it around and it looks like it will work. I’ll try and take a picture of what I’m talking about when I get home. The only place that I have a question is at the very ends of the rocker. You would be surprised at how little variation there is in boards when you look at change in 6" increments (over length). I’ve been imaging boards with aps3000 and I have been very surprised by what I’ve been seeing. However, just to play it safe what I might try is to just glue the middle half of the table down then see from there.
I gotcha. By the way, nice shop. You a cabinet guy?