What causes stress cracks on a boat?
- Swelling of the resin due to water diffusion.
- Wave action and rigging stresses.
- Direct sunlight or thermal shock on darker colored gelcoat can cause warping, delamination and blistering.
- Impact.
- Expansion or contraction.
What causes stress cracks in fiberglass boats?
We won’t go into great detail here, but suffice it to say that stress cracks occur because of voids under the surface of the gelcoat, and or a lack of strength in the underlying fiberglass or compounds used in the sub structure of the boat.
What causes gelcoat cracks on a boat?
These gelcoat cracks are stress cracks at the corner of a companionway. A concentrated group of cracks generally running in the same direction indicates a more severe problem. This is often found on the leading edge of the cabin top where it meets the deck. This can be the result of a high flex area enduring heavy seas or too much load on the boat.
Are You Afraid of cracks in your boat?
A lot of boat owners get very upset when they see these cracks, sometimes needlessly, while at other times their fears are well founded. Clients will often ask about cracks and the surveyor will be expected to provide answers.
What happens if you stress crack a gelcoat?
Stress Cracks Suck Water. Water loves to seep into stress cracks. This can pose a few different additional problems. If the area of gelcoat which has a stress crack right there, has fiberglass just under it, well, the hardened fiberglass will keep the water from just seeping into your boat.
How do you fix stress cracks on a boat?
2:038:44How To Fix Spider Cracks, Hairline Cracks, and Crazing in Boat ...YouTubeStart of suggested clipEnd of suggested clipSo for the amount of gel coat I've got in there two drops is going to be plenty. I'll have to mixMoreSo for the amount of gel coat I've got in there two drops is going to be plenty. I'll have to mix the catalyst well into the jaw coat. And remember that we don't have a lot of working time.
Are gel coat cracks normal?
Gel Coat cracks are common on everything fiberglass. Its just the fiberglass flexing and causing a cosmetic crack in the gel coat or paint. Most are not structual at all.Sep 10, 2004
How do you fix a stress fracture in fiberglass?
0:3019:35Fiberglass Repair ~ Stress Cracks - YouTubeYouTubeStart of suggested clipEnd of suggested clipWith some 80 grit paper and just coming in and spending a little bit of time because it's just suchMoreWith some 80 grit paper and just coming in and spending a little bit of time because it's just such a small area just coming in and in really grinding. This down until.
What causes spider cracks on boats?
Spider cracks can indicate impact damage or serious structural problems that will need to be addressed to prevent spreading, but most often they result from relatively inflexible gelcoat that is too thick. Stress by thermal expansion or when bulkheads and liners were installed can cause minor flexing.Jan 11, 2018
Are spider cracks normal in boats?
Spider cracks are non-structural damage to the gel-coat of a boat. This damage is often caused by slight flexing of the hull. These hairline fractures also occur in boats of the mid 1970's vintage which often had thicker gel-coat layers than newer boats.
What causes stress cracks in fiberglass boats?
Stress Cracking This can be the result of a high flex area enduring heavy seas or too much load on the boat. Cracks may also form at a bulkhead or other hard spots behind the fiberglass when the boat flexes, creating pressure.Mar 12, 2021
How do you fix spider cracks in a boat gelcoat?
In order to properly fix any spider cracks, you will have to open the cracks to fill them up correctly. This can be done by using a Dremel. Once the crack is open and it has a good size you can sand and clean the area. For cleaning, you may use acetone or soap and water.Nov 19, 2020
How do you repair damaged gelcoat?
Once the gelcoat has fully cured, sand the repair smooth (wet sanding works particularly well with gelcoat). You can start with 220-grit sandpaper and, for a really slick surface, finish with at least 400- or 600-grit. Finally, apply a coat of high-quality marine polish and your repair is complete.Jun 16, 2020
What are stress cracks on a boat?
Re: Stress Cracks#N#Stress cracks are cracks in the gel coat of a boat that let you know there is undue stress on a particular area or a problem under the gel coat. I have a 79 11ft Whaler and it is covered in cracks in the gel coat, but none seem to be wide enough to tell me there is a problem. They seem to be common on boats of that age. If it looks like the transom is about to fall off stay away, but if not, I'll bet you will have a hard time finding a boat with none.
What does it mean when an owner calls a stress crack?
Re: Stress Cracks. If an owner calls cracks, stress crack, he is letting you know there is a problem. Where is the stress crack is important, but unless you are 1) a skilled boat surveyor or 2) the boat is cheap and you are not going to cause more stress, stay away. It takes a lot to break a whaler.
Why does gelcoat crack?
Causes of stress cracks. The main causes of gelcoat crazing are due to stress and movement . Gelcoat is hard and brittle while by comparison the glass fibre laminate beneath is softer and more flexible. So if the laminate bends or moves, the gelcoat won’t bend with it and cracks as it is brittle.
What are the two types of stress cracks?
There are two main types of stress crack – linear cracks and star cracks. Linear cracks tend to run in parallel lines and star cracks spread out in a starburst type pattern. The patterns of cracks are a clue to what caused them:
What causes a linear crack?
Linear cracks – linear cracks indicate damage caused by bending or flexing.
What are the two metals used in hulls?
Steel and Aluminium Hulls. The two metals used for hull construction are steel and aluminium. These are both very strong materials and will last a long time as long as they are cared for, which primarily means protecting steel boats from rust and aluminium boats from electrolytic action. Read More.
What are the blind spots on a boat?
Boats have many blind spots, including the headsails of sailing boats. Always keep a lookout, stay safe and remember that... Boat engines come in all shapes and sizes and include inboards, outboards, petrol, diesel, electric and hybrid systems. Some engines are...
Can a GRP boat crack?
Stress cracks on GRP boats. It is quite common to find cracks in the gelcoat when inspecting the deck and superstructure of a GRP boat. A trained eye will be able to inspect these and know whether they are purely cosmetic or of structural concern. It is important to differentiate between a gelcoat crack and a scratch.
Can a boat have a leaky deck?
Leaking decks. Leaking decks are perceived as a nuisance by some boat owners, but if leaks are ignored a much more serious situation may well be developing, especially in the case of boats with balsa or plywood deck cores. So deck leaks do need to be investigated and dealt with. Read More.
What is stress crack on a boat?
Excerpt. Stress cracks are a commonly occurring phenomenon with reinforced plastic boats. A lot of boat owners get very upset when they see these cracks, sometimes needlessly, while at other times their fears are well founded. Clients will often ask about cracks and the surveyor will be expected to provide answers.
Why does gel coat crack?
The primary reason why stress cracks appear in gel coat is because gel coat is brittle and the laminate to which it is bonded is less so. Gel coat is basically a resin to which a large amount of coloring pigment has been added, pigments that are oxides of metals like aluminum.
Why does my sandpaper crack?
By far, the most common reason for stress cracking is due to improper structure design .
Where does stress riser occur?
A stress riser occurs at point in a panel or hull skin where a normally somewhat flexible area is suddenly made rigid without a means of transferring the imposed stress gradually to the rest of the laminate. A good example is a strut attachment to the bottom without any kind of doubler.
Why does my boat have cracks on the top of the cabin?
This can be the result of a high flex area enduring heavy seas or too much load on the boat. Cracks may also form at a bulkhead or other hard spots behind the fiberglass when the boat flexes, creating pressure.
How to repair cracks in fiberglass?
Repairing Minor Gelcoat Cracks 1 Use a rotary tool or scraping tool to open the crack into a “V” shape. You will need to go through the gelcoat to the fiberglass and open the full length of the crack. Next, use 80-grit sandpaper to scuff up the opening you created. Fold the sandpaper so you can get a corner of it into the opened crack. 2 After removing the dust, you can fill the crack with G/flex® 655, Six10® or WEST SYSTEM 105 Epoxy Resin®/20X Hardener thickened with 406 Colloidal Silica Adhesive Filler. 3 After the epoxy has fully cured, wash it with water to remove any amine blush. The blush is water-soluble, which means water is the best option to remove it. You can now sand and apply a color matching gelcoat to the area.
What to do if gelcoat cracks?
If the gelcoat cracks were caused by fiberglass flexing, add some fiberglass reinforcement to the backside to help prevent future cracks. If a screw hole repair has a fiberglass core behind it, seal the core with epoxy.
What is gelcoat on fiberglass boats?
Gelcoat is a pigmented, high-quality polyester resin used as the finish on fiberglass boats. Like any other polyester resin, it has good points and bad. Let’s look at some of the bad points that lead to cracking.
Can you spray gelcoat on a boat deck?
But when the builder sprays gelcoat on the mold of a boat deck with cabin top corners and seat backs, the edges tend to get more than needed. Or the gelcoat runs down and builds up in an inside corner, or too much or too little gelcoat gets sprayed on the whole mold.
Can gelcoat cracks be repaired?
When gelcoat cracking is a symptom of another problem, repairing the crack and not repairing the underlying cause could lead to repeated cracking. In the case of a thick gelcoat, thinning the gelcoat is not practical. After the repairs are completed, some boats remain crack-free for years.
