Vacuum Bagging, what is it ?

[farmo83]

After reading the awesome build threads from DCB, what is vacuum bagging and how is better then a regular lay up ? I'm sure it makes it stronger and maybe lighter. I know nothing about this and am just curious.

 

[RaceTec]

It is a method of wetting the composites that ensures a complete consistent amount of resin. It is lighter, stronger, and will prevent any voids or air pockets, if done correctly. Hand laying and wetting is the normal method, vacuum bagging is a step up, and using an autoclave with prepreg would be the best method.

 

[HCP3]

After reading the awesome build threads from DCB, what is vacuum bagging and how is better then a regular lay up ? I'm sure it makes it stronger and maybe lighter. I know nothing about this and am just curious.

I asked the same thing in one of their mold threads.

Find Tony @ DCB's answer here: https://www.riverdavesplace.com/forums/threads/m33-twin-400rs-lake-powell.196398/#post-3248265

 

[PlanB]

Brings back memories from the HotBoat forum. A certain DCB owner arguing that it was not needed for a “lake boat” when comparing their layup quality to Skater. DCB has obviously stepped up their game from those days.

 

[beaverretriever]

Brings back memories from the HotBoat forum. A certain DCB owner arguing that it was not needed for a “lake boat” when comparing their layup quality to Skater. DCB has obviously stepped up their game from those days.

Still not probably needed IMHO. Many companies are jumping on board because it's the only way to continue to build a boat in California per all the chemical building emissions laws hahaha.

 

[PlanB]

You get a lighter stronger hull, therefore you get better performance. The performance of my Skater after owning DCB’s made me a believer.

 

[HB2Havasu]

After reading the awesome build threads from DCB, what is vacuum bagging and how is better then a regular lay up ? I'm sure it makes it stronger and maybe lighter. I know nothing about this and am just curious.

Essentially a composite layup using the Vacuum Bag process allows for a tighter layup by removing the atmospheric oxygen while compacting the plies during the lamination process and curing cycle.

 

[lbhsbz]

It's like glueing 2 pieces of wood together with clamps, vs just buttering up tons of glue on both surfaces and setting them on top of each other.

If you clamp them, it squeezes all the extra glue out....or in other words, requires a lot less glue. If you just set the glued up pieces on top of each other...they won't be as tight fitting and will require a lot more glue between them to make a bond.

The vacuum bag is simply a big ass comformable clamp. This allows one to use just the right amount of resin in the layup while also assuring that all the layers are "clamped" together well such that we have a good bond between layers of glass and minimal extra resin (added weight) sitting on top/between things serving no purpose.

It makes a better joint....or lamination.

 

[footer]

Imagine taking the boat hull mold, with all the fiberglass and resin layed up in it, and putting the whole thing in a big plastic bag and then sucking all the air out of the bag, just like vacuum packing something in the kitchen. Except, instead of doing it to remove oxygen and prevent spoilage, you're doing it to get that atomospheric clamping effect that lbhsbz is talking about in the post above. What’s accomplished is a very even distribution of resin throughout the composite. The technology is a little more complex than just a big plastic bag, and the vacuum is never perfect, but this is essentially the process.

Two things about that clamping effect.

1. The clamping force is applied in three dimensions (instead of two like a press) because the work piece is surrounded in every direction by the atmosphere. This means the sides of the hull are getting just as much "clamping" force as the bottom of the hull. Equal forces applied from every direction onto the composite part.

2. The forces are huge. For simplicities sake, imagine we’re vacuum bagging a flat piece that’s 22 feet long and eight feet wide. And imagine we could accomplish a complete vacuum. At a typical atmospheric pressure of 14.7 pounds per square inch, we’d be applying 372,557 pounds of compression force to the work piece. 186 tons of force.

 

[jetboatperformance]

We sell fiberglass Buckets and benches for alot of boat and other applications The job shop uses tooling they made for us that is made from an inner and outer mold , the dry material is place in the "tool" then resin is injected in and fumes vacuumed out its called Light RTM process it also saves them on emissions costs

https://search.yahoo.com/search?fr=mcafee&type=E211US105G91208&p=light+rtm+process

 

[RiverDave]

After reading the awesome build threads from DCB, what is vacuum bagging and how is better then a regular lay up ? I'm sure it makes it stronger and maybe lighter. I know nothing about this and am just curious.

Vacuum Bagging is different than what they are doing. What they are doing is called "Infusion" it's a superior process to vacuum bagging.

For quick terms.. Hand Layup the guys will actually hand squeegee excess resin out. Vacuum Bagging is actually a giant bag that "squeezes" excess resin out via the bag and vacuum pressure. Infusion actually draws the resin through the material under a vacuum so there isn't any excess resin to begin with. Excess resin not only adds weight to the hull of a boat, but will actually cause the parts to be weaker than an optimal penetration.

Wes (Froggystyle) was the first person to bring this technology to the performance boat market when he was building the Trident Deck Boats. Previous to that it was an uber expensive process used primarily in Aerospace and exotic yachts etc.

RD

 

[RiverDave]

It is a method of wetting the composites that ensures a complete consistent amount of resin. It is lighter, stronger, and will prevent any voids or air pockets, if done correctly. Hand laying and wetting is the normal method, vacuum bagging is a step up, and using an autoclave with prepreg would be the best method.

Second best method.. The reason we don't see that on the West Coast is because the boats will start to post cure again do to the heat out here. Infusion is generally recognized as the best method for where we are at.

Ever seen a Skater with a 50,000.00 paint job and then a year later you can see it "imprinted" the fiberglass pattern through the paint? That's because it post cured at some point. They are light and strong, but that process is problematic for our climates.

RD

 

[buck35]

Second best method.. The reason we don't see that on the West Coast is because the boats will start to post cure again do to the heat out here. Infusion is generally recognized as the best method for where we are at.

Ever seen a Skater with a 50,000.00 paint job and then a year later you can see it "imprinted" the fiberglass pattern through the paint? That's because it post cured at some point. They are light and strong, but that process is problematic for our climates.

RD

I have heard my boat may have done by skater .its epoxy. And is in fact imprinted.the boat is black and I actually like the look but don't touch, lol
She's one hot bitch In the sunshine.
The pattern of the glass underneath is like faucets on a gem, and while you can't feel it it's visible.

 

[RiverDave]

I have heard my boat may have done by skater .its epoxy. And is in fact imprinted.the boat is black and I actually like the look but don't touch, lol
She's one hot bitch In the sunshine.
The pattern of the glass underneath is like faucets on a gem, and while you can't feel it it's visible.

There are other people out there that do that process other than Skater. Schiada has built a few race boats that way etc..

RD

 

[buck35]

There are other people out there that do that process other than Skater. Schiada has built a few race boats that way etc..

RD

I don't really know Dave, just what was suggested on oso once. Its kind of a one off fountain from what I've been able to learn, which ain't much in a honesty.

 

[RiverDave]

I don't really know Dave, just what was suggested on oso once. Its kind of a one off fountain from what I've been able to learn, which ain't much in a honesty.

I’d be surprised if Fountain hasn’t built epoxy boats with their race heritage. I honestly don’t know a lot about them

 

[RaceTec]

I am sorry I misspoke, when I was referring to a wet layup I meant a hand wetted layup with vacuum bagging (I think this has been done by builders such as Eliminator?). In reality there are many techniques that can be use with composites. The most common being a normal rolled out hand applied wet layup, to the most advanced in the industry that I know of being DCB's vacuum infusion process. In the automotive, aerospace, and racing industry the most advanced processing that I have personally been involved in has been two side molded prepreg (as mentioned above with the seats) or autoclave prepreg processes. There is a significant structural strength difference between a wet layup with a resin and epoxy layups which are typically prepreg materials.

Now just a guess why you would see weave transfer patterns in a Skater versus a DCB would be more based on the Gelcoat being used as compared to a paint system. The gelcoat provides a significant "layer" between the mold and composites. (I think Skater uses a less significant gel coat?) As for temperatures when and where the layups are going on all of that is figured based on the layup schedule, all of the manufacturers of epoxies and resins have conversion charts based on these variables. Now I have been out of composites for years so I may be wrong on a number of these points but I would love to hear a response from @Tony DCB Boats who seems to be offering the most advanced layup schedules in the industry?

 

[Tank]

I’d be surprised if Fountain hasn’t built epoxy boats with their race heritage. I honestly don’t know a lot about them

Fountain didn't epoxy boats. They, like Cigarette and others would have Skater do the Epoxy boats for special one offs.

Outerlimits has been doing Epoxy boats for many, many years. Kinda their claim to fame.

Funny thing is people love or hate epoxy boats. They're light and fast but ride more rigid than glass.

 

[fmo24]

And just to muddy the water on what racetec wrote “prepreg” is impregnated material such as carbon fiber with a b staged resin so it is tacky but not wet. The resin flows under temp and Pressure such as in an autoclave which is just a giant pressure cooker. There is resin systems in development that will cure under ultraviolet light which would negate the requirement of an autoclave for some parts

 

[buck35]

Fountain didn't epoxy boats. They, like Cigarette and others would have Skater do the Epoxy boats for special one offs.

Outerlimits has been doing Epoxy boats for many, many years. Kinda their claim to fame.

Funny thing is people love or hate epoxy boats. They're light and fast but ride more rigid than glass.

If I remember, this was as per glass Dave. He's pretty much the resident expert over there.i really had no idea until I asked about the pattern in the glass and he said it was common in epoxy layups. RF111 posted up a pic of my boat on Facebook once ,kind of blew me away.

 

[Tank]

If I remember, this was as per glass Dave. He's pretty much the resident expert over there.i really had no idea until I asked about the pattern in the glass and he said it was common in epoxy layups. RF111 posted up a pic of my boat on Facebook once ,kind of blew me away.

You most likely have one of their old epoxy race boats. They weren't actually 'super rare'. They had Skater build up a lot of epoxy boats for racing, kilo's, etc.

 

[buck35]

It's an all black 24, with red and gold graphics on the side .dought it was ever a racer.

 

[manxman]

Infusion is the strongest and lightest way to build a hull, but not the cheapest, and there is a huge learning curve if you have never done it. All the tooling needs to be sealed and reinforced to handle the pressure. We made outrigger canoes with the infusion process and a 30' canoe hull only weighed 186 lbs. 4 days to prep, and only about 20 minutes to actually infuse the resin!

 

[footer]

View attachment 729327 Infusion is the strongest and lightest way to build a hull, but not the cheapest, and there is a huge learning curve if you have never done it. All the tooling needs to be sealed and reinforced to handle the pressure. We made outrigger canoes with the infusion process and a 30' canoe hull only weighed 186 lbs. 4 days to prep, and only about 20 minutes to actually infuse the resin!

Cool progression of images!

 

[Gramps]

I thought vacuum bagging is how you store extra weed

 

[Gelcoater]

Now just a guess why you would see weave transfer patterns in a Skater versus a DCB would be more based on the Gelcoat being used as compared to a paint system. The gelcoat provides a significant "layer" between the mold and composites. (I think Skater uses a less significant gel coat?) As

Probably not.
Transfer will show through gelcoat even of multi layers.
Consider also, those Skaters are painted. Read body work and sanding before paint.
Some time later the print or transfer returns through the paint.
I’ve no idea what resin system DCB uses but I’d suspect a vinyl ester resin vs Skaters epoxy system.
Considering how cold it gets in Michigan I’ve always been amazed they can even get anything to dry there,lol.

 

[jetboatperformance]

nite and day difference on my seats the inside used to look like a hand layup finish

 

[checkrd past]

It is a method of wetting the composites that ensures a complete consistent amount of resin. It is lighter, stronger, and will prevent any voids or air pockets, if done correctly. Hand laying and wetting is the normal method, vacuum bagging is a step up, and using an autoclave with prepreg would be the best method.

I 2nd that.