How Much Epoxy for RV Delamination Repair? Sizing by Wall Area
11 October 2026
Sizing an RV delamination repair kit is one measurement and one number: the square feet of loose skin, times about 4 fl oz of mixed epoxy per square foot. A 48 oz kit covers about 12 square feet, 96 oz about 24, and 1.5 gallons about 48. The part people get wrong is the measurement, because the loose area is nearly always bigger than the bubble.
Measure the loose area, not the bubble
The bubble is only where the skin has lifted far enough to see. Around it is skin that has let go but is still lying flat. Epoxy has to reach all of it, or you glue the middle and leave a loose ring.
- Press the wall with the flat of your hand, starting at the bubble and working outward. Loose skin moves and sounds hollow when you tap it. Bonded skin feels solid and sounds dull.
- Mark the line where it turns solid with painter's tape, all the way around.
- Measure the taped area as a rectangle, height times width in feet. Round up. A loose area 3 ft by 4 ft is 12 square feet.
Do this in the shade or in the morning. A wall in full sun bulges more and makes everything look worse than it is.
Why 4 fl oz per square foot
The glue line you are filling is thin. One square foot at a given thickness holds this much liquid:
| Glue line thickness | Epoxy to fill 1 sq ft |
|---|---|
| 1/64" (0.4 mm) | 1.2 fl oz |
| 1/32" (0.8 mm) | 2.5 fl oz |
| 1/16" (1.6 mm) | 5 fl oz |
A pressed-flat joint lands around 1/32", which is 2.5 fl oz. The rest of the 4 fl oz is what the job actually uses: dry plywood backing soaks some up, some squeezes out at the edges when you press, and some stays in the syringes, tubing and tubs. Sizing at 2.5 means running out with the wall half done. Sizing at 4 means finishing with a little left to fill the holes.
RV delamination repair kit sizes
| Loose area | Mixed epoxy | Kit size | Syringes with tubing | Batches of 12 oz |
|---|---|---|---|---|
| Up to 12 sq ft | 48 oz | Small | 2 | 4 |
| Up to 24 sq ft | 96 oz | Medium | 4 | 8 |
| Up to 48 sq ft | 1.5 gal (192 oz) | Large | 6 | 16 |
For scale: 12 square feet is a bubble or two beside a window. 24 is a 4 ft by 6 ft section. 48 is most of a sidewall between two openings.
All three are the same RV Delamination Repair Kit: thin epoxy with a 2:1 slow hardener, large syringes with flexible tubing, graduated quart mixing tubs, a spreader and stir sticks. Only the quantities change.
The kit for this job
RV Delamination Repair KitThin 2:1 epoxy, injection syringes with tubing, mixing tubs. Sizes for 12, 24 or 48 sq ft.See the kit
When to go one size up
- Your measurement is within a couple of square feet of the limit. An 11 square foot job on a 12 square foot kit leaves no margin.
- The backing is very dry. An old leak that dried out years ago leaves thirsty wood that drinks the first pass.
- The gap is wide. If you can slide a finger behind the skin at the opening, the joint is closer to 1/16" until it is pressed, and more will squeeze out.
- More than one wall. Add the areas together before you choose.
Leftover epoxy keeps. Unmixed resin and hardener store well with the caps on tight, so what a size up leaves over is there for the next repair.
Batch size and working time
Do not mix the whole kit at once. A full tub of mixed epoxy heats itself up and kicks early. Mix 12 oz at a time: 8 oz resin to 4 oz hardener by the marks on the tub, stirred for 2 minutes. One batch covers about 3 square feet.
With the slow hardener a batch has 35 to 40 minutes of pot life at 80°F (27°C), longer when it is cooler. That is enough to inject one batch, press that section, and mix the next. On a 24 or 48 square foot job, work across the wall in sections and get the boards on each one before moving on.
Frequently asked questions
How much epoxy do I need for RV delamination?
About 4 fl oz of mixed epoxy per square foot of loose skin. Measure the area where the skin moves when pressed, not just the visible bubble. 12 square feet needs 48 oz, 24 square feet needs 96 oz, and 48 square feet needs 1.5 gallons.
What size RV delamination repair kit should I buy?
Match the kit to the measured loose area: the 48 oz kit for up to 12 square feet, the 96 oz kit for up to 24, and the 1.5 gallon kit for up to 48. If your measurement is within a couple of square feet of the limit, or the backing is very dry, go one size up.
How many syringes do I need to inject an RV wall?
Two for a job up to 12 square feet, four up to 24 and six up to 48. A syringe can be refilled through a session, but epoxy cures inside it once you stop, so a larger job done across two days needs a fresh set for the second day.
Can I use less epoxy if I press the wall harder?
No. Hard pressure squeezes epoxy out of the joint and leaves it starved, which is a weak bond. Use firm, even pressure from flat boards, and size the job at about 4 fl oz per square foot so the joint stays full after the squeeze-out.
How long does leftover epoxy last?
Unmixed resin and hardener keep well stored capped, cool and dry, so leftovers from a larger kit are usable on the next repair. Check the date on the bottle if it has sat for more than a year. Mixed epoxy does not keep: a 12 oz batch with slow hardener has 35 to 40 minutes at 80°F before it starts to gel.
What You Need For This Job
- RV Delamination Repair Kit: thin 2:1 epoxy with injection syringes, tubing, mixing tubs and sticks in three sizes, 48 oz, 96 oz and 1.5 gallons
- Fumed silica: thickens the last of the epoxy into a putty for filling drilled holes
- RV & Camper Fiberglass Repair Kit: for cracked or holed fiberglass, which injected epoxy does not fix
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