How do I mend this deck?

Thread starter #1
Hi All

This is my first post here though I've been lurking for a while.

I've just bought a very cheap Laser which I was told had a professional repair to the mast step which was why there were two plastic blocks bolted to the deck and some plastic reinforcing inside.

It looks to me as though someone has repaired the mast step but put the inspection port too close to the mast. The deck has then cracked and been repaired or maybe they didn;t repair the mast step in time.

The picture shows there are cracks in the deck some distance from the mast and the area between the inspection port and the mast is very soft with a soggy core.

My inclination at the moment is to grind off the outer skin and the foam core. Repair the inner skin with some mat applied from above, recreate a core - maybe with plywood for extra stiffness and finish by repairing the outer skin with mat. Maybe put some reinforcement around the inspection port too.

I'd be grateful for comments or suggestions.


wow.. what a trainwreck!

i'll bet gouvernail wil lhave some good answers for you.

you might shoot him a PM if he doesn't respond here.

best of luck
i'll bet the top bit of the inspection port might peek outside the patch kit.
however, email aps & see if they have the specs & measurements for the patch kit. there also may be enough of some unrotten (is that a word) deck that you could scab in to fill the inspection port hole... that is if you use the patch kit from APS.

Hi Russell,

I guess we may now know that "Professionally repaired" may actually mean the repair was made by a Professional, who might have been a dentist, lawyer, or even a Professional wrestler? lol, (just kidding if you are one of those!).

More detail would help?, Year? pics of step bottom? other major problems? Intended use?

But it sounds like these patches prevented a failure, so I'd pull out any "repairs" inside as well, let it dry with a light on (forever!), then analyse, and make a decision. If the deck is soggy (wet) it may be wet everywhere, and if frozen a few times, may have trashed the whole thing. The symptoms are discussed previously on other threads, but loose top layer on side deck or cockpit sole, are places to look.

Of course weigh it. (95%+ of anything over 132 lbs is water, and may have been there for years).

If the rest seems worth saving, and since you seem competent, you have the right idea. You can save the top layer if you want to try for a cosmetic patch, or just skip it and cut out a big piece, fill as you described, and fair it over and match the color as best you can.

If it's truly soggy, soft, etc around that port, and your final cosmetics aren't a big concern, then I'd cut the top layer in a big triangle, or diamond, and nicely symetrical. I'd go outside the port, and end up filling that area. I wouldn't use the kit, as it's quite expensive, and cosmetically just a patch when you are done.

I've done a few by cutting thru the bottom. Then it's easy to stiffen the deck, replace a worn tube, etc. And the final patch of the bottom is very easy to fair nicely. That is a different topic though.

But I'm assuming you are competent with glass, and have 4-5 months of winter to putz with this, and that the rest of the hull is worth saving. And that cosmetics, or final weight aren't going to cut into your chances of an Olympic berth.

The bottom of the mast tube needs to be much stronger than the deck area, so don't bother if you can't make that part really strong.

Good luck, and welcome to Lasers.

Al Russell
Thread starter #6
Thanls Al and others.

It's a 1979 boat and the rest of it looks pretty good The bottom of the mast step looks OK (see pic) and the only reason to worry about that is that it might have been done by the same person as the deck.

I'm planning to use it for club racing but as I'm generally at the back of the field then the Olympics will need more practice.

The repair kit isn't available in the UK as far as I know and anyway it costs more than I paid for the boat and most of it's gear.

I'm not sure I need to cut it out symetrically. I thought I could just make the final layer of glass symmetrical. and it's probably best to destroy the minimum I need to.

I think you're right that it might be better to repair the hatch hole too.

The issues I'm still wondering about are how to join the repaired area to the original area to avoid a hinge effect which might lead to cracking and a related question of what to use for a core - bearing in mind that the core would have to be bonded to a surface that might be uneven.

Any more ideas?





Active Member
The crack at the edge of the deck repair doen not worry me all that much. If it is soft under it, I would grind it away and re fill it. Usually if I am fixing the deck in that area I put some glass around under the deck as well. Fishingmickey just had me repair his mast step. We thought it was coming loose at the bottom and put in an inspection port to get at the inside. I took a bunch of photos and cn scan them to my website. I am suppoed to be working right now so the page will be very simple but I should have it up in a few minutes.
Thread starter #9
Thanks for all the advice and especially for the pictures.

At least now I've got a plan.

I'm going to try and put the deck back like it should be - fibreglass top and bottom and core in the middle - probably resin and glass bubbles for the core. I don't know yet how much I'm going to replace but if I can mend cracks then that's easier than rebuilding a lot.

Of course it depends what I find when I start grinding.

First priority is to get it inside and drying and I've arranged somewhere to put it on it's side indoors for a while (in the garage with a couple of floor to ceiling props to lean it on).

Thanks again



Active Member
General rule>>
If it is wet something is wrong with it.

Most stuff in a Laser does not soak up water. If the Laser is holding water there is almost always accompanying delamination. When I am trying to get long lasting repairs I remove anything that is wet before it has a chance to dry out. I might occasionally remove and replace more than necessary. The other option is to dry things out, lose the indicator of "It is wet and therefore something may be screwed up" and sufffer later when the "dried out part" delaminates again and soaks up water again.

Note: I am somewhat of the industry renegade on this subject. Ignorant people all over the world have written for years about drying out blistered keelboat bottoms. They and hundreds of repair shops all over the world ignorantly tell ignorant customers about the necessity of drying laminates and moisture content and all sorts of things totally unrelated to repairing osmotic blistering.
It seems we have a sailing community made up of people who never paid attention in high school biology class.
The only way to fix a blister is to remove the soluable chemicals that won't pass through the semipermeable membrane.

Note: If John Kerry had written this note:

You can study high school biology and chemistry and work hard and get good grades or you can be stuck with a blistered bottom.
Thread starter #11
I think we may have different ideas of dry. Since I started this thread a 6 inch deep pool has collected in the cover of the boat. I can't tell what's wet as everything is! I think we have more rain here than in Texas.

More seriously - that's a good point - I'll start my investigation as soon as its dry enough to work on.

Thread starter #12
This is turning out to be a bigger job than I thought - so much so that I have another hull lined up - but I'm going to try and put this one back together first.

Repairing the deck has proved difficult because of the large lumps of resin on the inside from the previous repair - so I've taken the dramatic step of cutting away the damaged deck and grinding away the previous repair. This seems to be a good move - resin appeared to have been poured in with a bucket - the area around the mast (about 12" square) was about 1" thick. Grinding these repairs out has reduced the weight by 19lbs! It's probably dried a bit too with the extra ventilation.

I've started putting it back together and today's question is do I need to replace the plywood around the mast step - it seems easier and probably stronger just to glass the step in place.

I've attached a picture to amuse you too. Can you think of any reason (sensible or not) why someone thought it was a good idea to saw off the bottom of the mast tube.



Is the object in the picture a piece of the mast tube? If so, what does your mast tube look like now?
I would use some plywood there. It is lighter and it will be easier to shape (a circle). After that you can put fiberglass and expoxy over it.
You will also need to fiberglass the deck back in one piece. I would build it up on the top. Just make sure it is straight (tape off the part of the deck that does not need to be glasses) so that it does look professional. Paint layers of epoxy over it and sand so that it becomes an even repair. Some automotive spraypaint in the color of your deck (off-white) will nicely finish the job.
please post some pictures of the deck and mast tube.

Thread starter #14
Hi Georg

Yes. It's the bottom of the mast tube - it was still in place and full of resin - but it's clearly been sawn off.

My mast tube looks just like a mast tube - only shorter. I've ground the end down and i've started lengthening it using the top of an aerosol as a former. Pic attached.

It's difficult to do a picture of the deck but I've attached a picture of the hole - you can see where I've fibreglassed over my grinding and over the big blob of yellow filler in the bottom of the boat.

And if anyone's wondering - yes I do have more spare time than money.



Wow! We should redefine the word "professional" for sure!
They probably cut off the tube, because they had no idea that it is actually sitting in something else. They probably saw it as a whole and the only way to get access to the damaged part was - they thought - to cut it in two pieces.
Two things: That bottom piece should be REALLY strong.
Make sure you get the bottom piece back at the right spot. If it is too much forward your boat will be slow. If it is too much aft your boat will be fast (up to a certain point) but illegal. If it is off to one side, well who knows what will happen, but it ain't good. Create a bottom piece at the right spot and let the other piece slide in there (as it is supposed to do).
Good luck!

Thread starter #17
Here's the latest update on the repairs. The picture shows the jig I made to get the mast step in the right position. I set it by putting it in an undamaged boat and using a couple of G clamps to lock it in place. The mast tube is a snug fit on the jig so that holds it while I fibreglass the bottom in place.

It worked well - at the second attempt - the first attempt showed the jig wasn't snug enough side to side but the second attempt was good. I put the bottom mast in and measured the rake - the same to each corner of the transom and 151" to the centre which is within the range quoted elsewhere on this site. Mast step is 14" deep but still needs a plate in the bottom.

I think I'm going to call it Lazarus.



Thread starter #18
There's a bit of a delay on Project Lazarus now while I sort out the materials needed for the rest of the repair. I'm pleased with the way it's gone so far so I'd like to try and put the deck back properly - it took me a few phone calls to figure out what I needed though. Eventually I found a really helpful man at the UK distributors of Airex foam who knew exactly what foams and densities had been used in Lasers since the beginning.

The original type foam is 55 kg/m3 but is only available in large sheets which makes it prohibitively expensive for my repair (not to mention carriage) but he suggested using the green foam used in later Lasers (Airex C70.55) or given that it was around the mast step a denser version (Airex C70.75). I'm going to go for the denser foam - for the area I need it will be about 30 grams heavier - although it's more expensive it'll be slightly cheaper because of the sheet size.

Looking forward to the ongoing repairs Russell,my 1979 boat is just starting to go round the mast lip,but have been putting it off and putting it off,think i'd better make a start before it reaches your herculian task!!!
I think you can purchase a mast step repair kit. I did a Goolge search and saw some pics of one done on Boothbay Maine. Here is a link for someone who may sell them. HTH