Question for deck builders about delamination!

I just finished pressing my first deck, I wanted this thing to be super strong…a perpetual tank! I am using a vacuum bag with a pretty substantial vacuum pump capable of holding 26-28 hg for 8 hours easily.!

Everything looked perfect until tonight, starting to cut it out!

So the deck is built up of 9 plys of sugar maple with one layer of bidirectional fiberglass at a 45 degree angle.

It looks like I have delamination at the fiberglass layer and now I’m pissed!!! Is there anything I can do to fix this or should I just work this layer out (will end up taking off 2 full layers of maple).


If I take it off, I’m down to 7 layers and I’m 265 lbs so i would have to figure out a way to press 2 more layers.

I currently have one more piece of crossband and one face grain piece…but my mold got destroyed! photo-1(1)


Oh yea, I got freaked out and filled the gap with a bunch of glue and threw like 8 clamps on the section that the delam was happening.

I stopped cutting and only have one end part cut out a bit.

Did you laminate it with fiberglass resin or wood glue? I don’t think glue will work with fiberglass.

All the wooden layers were with titebond 3 and the layer with fiberglass was with resin. I put resin on both pieces of wood and the cloth itself until it was fully saturated and then into the vacuum bag for about 8 hours

what type of resin did you use epoxy or polly

I have used both and epoxy is tricky cuz if you don’t get the mix right it won’t Harden at all.

It was Bondo polly resin

And the bottom 2 layers, that fiber glass is stuck to them like crazy!!

Sorry, I can’t see why it would delam then.

Yea, I’m pretty confused too! I’m hoping I can just pull it apart and vacuum bag up too more layers. Think there would be any issue there?

why not just clamp it? Let the resin run out the edges and sand it off later?

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So I should lay up more resin in between the layer and clamp it down for a bit?

@Sololongboards or @treenutter might be the ones to ask about this? I wager starting again might be the sure fire way to be able to rely on it?

I was hoping that wasn’t the case…I’d have to recarve a new mold and buy more wood! But if its completely ruined, I guess thats what I will do!

I’m no expert at pressing decks. One of those two should hopefully give you a point in the right direction.

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@Itsmedant it looks to me like your fiberglass layer didn’t make sufficient contact with the wood layers during the press. Or - it might have made contact but there was a dry spot so the resin didn’t adhere to the wood and composite. Or the resin had some inconsistency at the failure location and didn’t harden. I don’t use Bondo so I don’t know about it’s working time or other properties. Another potential failure point is the pressure that the vacuum bag can create… if you have more extreme bends to the wood you might not get perfect contact with every layer. Simplifying your mold would be the solution in that case.

Unfortunately you can’t know how far into the deck this gap is without cutting the deck in half. If there is a failed contact point between the layers a little but of use will weaken that area and the deck will likely crack.

If you managed to get additional resin to fill the gap all the way inside the deck, and the wood could still “move” with your clamping to make contact with the composite layer, then maybe you could salvage the workpiece you’ve got. My opinion is that this is unlikely to work though.

My advice is to take what you’ve learned and start over with a new workpiece.

You should be proud man, designing and constructing a deck is difficult. I practiced and refined my process for a long time before I had a good result.


Thanks for the reply, you telling me that I should be proud of this deck is some amazing feedback coming from the master himself!!

So here are my thoughts…I’m going to finish cutting out the deck to see if the delamination happened throughout the entire deck or just in that one spot. I clamped and glued that spot over night and it looks like it held really well.

If it did happen over the entire deck, the sample piece came apart really clean so maybe I can remove that entire section from the deck. If I can get it all off cleanly, I can throw it back into the vacuum bag with a new “support mold” and put 2 more layers on. I did this board 1 layer at a time (8 hours in the bag each) so I got pretty good at keeping everything true and getting an additional layer on each time.

For my next deck build, I just went to the store and got 3 8 ton hydraulic bottle jacks and I’m going to start cutting a mold out of wood so I can build a press similar to the one @longhairedboy documents in his blog.

In other news, the piece that I cut out, even with just the 7 layers, that thing is rock solid!! I just don’t know if the deck at 7 layers will be strong enough to make into and esk8!

Thanks again for your reply and advice @treenutter, it really means alot to me for you to take the time to give me the advice!

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I’m on my third press. Don’t build the first or second one. The last one is the one that’s been working for three years almost, but the frame is starting to bend and crack so i’ll probably build another one soon after i buy a planer so i can properly laminate the timbers. The one i have now is just carriage bolted and screwed and glued, but i didn’t bother to plane it, which was a mistake.

The next one will probably last longer, but it will also be wooden if i don’t just give in to my dreams and spend the money on c channel and the time to drill all of it so i can bolt together a steel one. IF i was to do that the fasteners alone would ikely cost as much as my entire wooden press, but it could take like 40 tons.

Is this the 3rd one?

I have some ideas on how to build one with some stuff I have laying around. I won’t be pressing as many decks as you to begin with! Maybe 4-5 a year depending on my friends and how good the decks actually turn out. I have a few more designs I’m working on so I want to keep going with this stuff…the vacuum bag is just hard to do more complex curves on.

yeah that’s the one. that’s the good press frame. It hasn’t exploded. yet.

As far as my mold goes, i paid a guy to help me design it and then he machined it and mailed it to me. Cost me about $500 total for the mold because it was heavy and cad work/machining can be expensive, but i feel its been worth it.

At the moment i’m using a pair of 6 ton jacks from Autozone. I was using a pair of 2 ton jacks, but i’ve seen improvement in consistency of lamination after stepping up to 12 total. If i go with steel for my next one i can use any kind of jack basically, even a fancy air/hydraulic one but i’ll most likely stick with simple automotive bottle jacks for simplicity.

I’ve also thoguht about vertical lamination but i really don’t see the point in it. And i’ve thought about adding heating elements to my press mold to warm the mold and press the veneer using thermally activated glues so i can pop out blanks in an hour instead of a day… but what’s the point really. And i don’t like the smell of cat piss when i’m machining, sooo…


Dang, thanks for all the advice! I’m going to try and make one, maybe over this weekend if I have time.

So do you think the deck this post about is completely screwed? Or theres a possibility to add 2 more layers on to it and save it?