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Paper Tiger rebuild


davidald

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Hi all. I just acquired what seems to be a Paper Tiger. Needs TLC and I am going to need any tips I can get LOL. I have posted some photo links in the 14ft forum under "14 ft somethingarother" I didnt post here initially because I did not know what it was.

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G'day David,

Like Tom says, there are plenty of people who sail Paper Tigers who are willing to assist. Posting questions here is an easy way to get more info and, if those of us who post here can't answer the question, we can put you in touch with various experts who can help.

Welcome to the class!

Regards,

Dave Stumbles

Secretary

Paper Tiger Catamaran International Association.

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Thanx Dave. I am actually posting pics in the 14 foot thread as the repairs progress. However I already have my first dumb question. I noticed the glass and gelcoat on the cat is quite thin. I am used to working on fibreglass truck bodies which are much thicker. I wish to pull/push the dents out of the hull and reinforce them from the inside but I am not sure as to the best way to do it. Anyone pulled dents out of a fibreglass hull before?

[This message has been edited by davidald (edited 21 March 2007).]

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The fibreglass layer is thin on foam sandwich boats, as the strength/stiffness comes from the separation of the two layers (by the foam). The distance between the layers makes it harder to bend the structure, much the same way as an 'I' beam works.

Depending on the size of the dents, I would be more inclined to fill them. A mixture of resin and 'microballoons' or 'Q cells' is a lightweight but stong way to do this. It is also easily sanded. The microballoons are tiny spheres that really look like a powder to the naked eye. They bulk out the resin mixture but, because they are hollow (there is now more air for a given volume), the weight per volume is reduced.

Flowcoat can then be applied over the top for a good finish. My non-technical understanding of Flowcoat is that it is like Gelcoat, but has a wax that forms on the surface to seal it off from the air to enable it to cure. If Gelcoat is used, it tends not to cure, as it isn't sealed off from the air like it would be when in a mould.

More than happy for people to correct any of this, but this is the way I have done dent repairs on my foam sandwich boats.

I would be very cautious about removing material from the boat, especially gelcoat or fibreglass. This will only reduce the integrity of the structure and make it more likely to fail. A good clean up of the existing gelcoat with a good car polish is a preferable option.

Regards,

Dave.

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Thanks Dave. I guess I will have to sand back to the glass where i need to bog. Never heard of these microballoons or the alternative to gel coat but I will ask around and try to find some.

The other hull is bad. I only inspected it thismorning and it has severe damage underneath. Looks like it was towed with water in the hull and went over a largew bump. There is an actual tear through the bottom like someone attacked it with an angle grinder.

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Hi David,

I agree, it's better to avoid sanding off gelcoat or fiberglass if possible. A good way to determine what the inside of your hull is like is to take a digital camera and put it through your hatch and take pics (takes a few to get the angle right)

I disagree with some people's thinking that you have a Jan Lindsar boat, i think it's one made by Derrick Congerton, my first PT was one of his, and it has a red foam core that is very brittle, and the inside layer of glass sometimes delaminates (it did on mine). If you see very dry looking areas when taking photo's inside your hull, this is likely what has happened. (if you press on the outside of the hull at these points it will feel softer)

Depending on the size of the dents, there are different ways to fix them. For small dents (less than a few cm's) Dave's way is great. For bigger dents, most likely the laminate will be separated, and will need to be replaced or repaired.

If you aren't too concerned about weight, it's possible to cut the affected area out of the hull with a jigsaw (on as big an angle as possible to get a large taper on the cut). Re-laminate the foam, make an overlapping backing ring around the inside of the hull, and re-glue the repaired section with another ring of fiberglass around the outside join. Then fair and re-paint.

It's hard to explain, and not that easy to do either, but not all that hard. Repairing foam-sandwich is never going to be simple.

Just remember that if you see white inside the hull, it means that the inner layer of fiberglass is delaminated, and water will be getting into the core. (bad news). This will all have to be repaired and if a large area of the hull is affected, it's not worth it.

As for re-finishing your hull. If flowcoat sounds too hard, i have had good results using a 2-pac primer/undercoat called "amercoat", followed by acrylic laquer. It's not as hard as gelcoat, but unless you are using it on the bottom of your boat or on your foils it lasts just as well.

One step at a time and you'll get there!

Cheers.

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Thanks Tom. I have a freind with an industrial spray setup for gelcoat so that part should be easy. The entire inside of both hulls is like linen or cotton finish. I cant actually see nthe glass on the inside because of this. I will have a go at fixing them but I also need to find out how much replacement hulls cost, if they are available. I have seen a couple of reasonably priced (less than $1000.00) cats in good condition so I dont want to spend much on this project. We'll see.

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Hi All

When cutting fibreglass or foam sandwich, use a diamond blade in an angle grinder, its very neat and doesn't do any damage outside of where you are working, you can still cut or grind your taper around the hole for patching.

Now that the novelty of diamond blades has worn off, they are as cheap as chips. The ones that are all plain except the outside rim of the blade seem to be best for fibreglass.

Just my experience.

Regards

Matt

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Would you guys mind describing some of the terms used here as some of us have had very little experience with building or repairing hulls.

What is gelcoat?

The finish on my boat is lousy. The bottom needs some TLC, if it was a wood boat, I'd fill the scratches and scores up with a filler then paint over it. Is this appropriate for a foam boat?

I've read some advice on bringing a hull up to speed by using car polish. Would this be better than a repaint?

There are some pics of my boat at www.bur.st/~shwell could someone identify where the hulls are from. Some of the pics a pretty big. They are foam and the last owner believed from S.A. but couldn't be sure.

Regards,

shwell.

[This message has been edited by shwell (edited 23 March 2007).]

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Hi Shwell,

That boat is a Jan Linsard boat, vintage around 84-87 i would say. It did originate from SA.

Look above at what Dave has written about refinishing small scratches and dents in your hull.

To get the gelcoat looking good, i start with fibreglass cleaner (very diluted hydrochloric acid). Then buff and polish like you would for a car paint job.

You might be surprised how well the hulls come up.

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G'day Shwell,

Gelcoat is the usual topcoat for fibreglass products. It is 'painted' into the mould before anything else so that it is what you see on the outside when it is removed from the mould. It is what gives it the good finish and colour.

Painting of foam sandwich/fibreglass should be an absolute last resort. A cut and polished hull will come up well assuning there aren't any large scratches. Even with scratches, a repair is better than a paint job.

The boat in your picture definitely looks like a Jan boat. His trademark is the 'undercut' gunwales, which make lifting them very easy (easily gripped).

Regards,

Dave.

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  • 4 weeks later...
  • 3 months later...
  • 8 months later...

Hi guys. Sorry to be absent, I have been in the hospital on and off for a few months. I have decided to sell, afraid there is no way I can finish this project. The holes in the hulls have been repaired (by The Fibreglass Factory Lonsdale).

Thanks for your help in this forum. I will know look to buy ho hum.

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